Botswana. This is because the vapor pressure of water increases with temperaturethe operative principle behind everything from hair dryers to dehumidifiers. Some electronic devices can detect such a change and indicate, when plugged in and usually with a small droplet symbol, that they cannot be used until the risk from condensation has passed. Three primary measurements of humidity are widely employed: absolute, relative, and specific. If the wind speed should increase to 30 mi/hr (with no change in air As airliners descend from colder altitudes into warmer air (perhaps even flying through clouds a few thousand feet above the ground), the ambient relative humidity can increase dramatically. It remains positioned over a region for extended periods and, as a result, takes on the characteristics of the surface it covers. Relative humidity is an important metric used in weather forecasts and reports, as it is an indicator of the likelihood of precipitation, dew, or fog. "Density Altitude" is the pressure altitude adjusted for non-standard temperature. As a result, absolute humidity in chemical engineering may refer to mass of water vapor per unit mass of dry air, also known as the humidity ratio or mass mixing ratio (see "specific humidity" below), which is better suited for heat and mass balance calculations. to the saturated vapor pressure of pure water: The enhancement factor is equal to unity for ideal gas systems. The slower the movement of thunderstorms, the higher the rainfall potential in one area. Forecast Discussion If the heat index is very high or the wind chill index is very low, then we must take safety measures to protect our bodies from possible effects of the weather, including heat exhaustion, sunstroke, and heat stroke in the summer, and frostbite in the winter. Absolute humidity is expressed as either mass of water vapor per volume of moist air (in grams per cubic metre)[3] or as mass of water vapor per mass of dry air (usually in grams per kilogram). When the humidity is slight (Figure 5a), under the influence of northeasterly airflow, the AOD in the Guangxi area is high, but the effect of the GBA is relatively small, for which the AOD is 0.61. Low Temp: 40 F. National Oceanic and Atmospheric Administration Football Weather, Local Information In the summer the hot dry air is absorbed by this ocean and the temperature rarely climbs above 35C (95F). If the air is totally saturated at a particular level (e.g., the surface), then the dewpoint temperature is the same as the actual air temperature, and the relative humidity is 100 percent. British Standard BS 1339 (revised), Humidity and Dewpoint, Parts 1-3 (2002-2007), Lans P. Rothfusz. The Antoine equation is among the least complex of these, having only three parameters (A, B, and C). WebA city located on the coast of North America has warmer winters and cooler summers than a city at the same elevation and latitude located near the center of North America. s {\displaystyle e_{w}^{*}} In other words, relative humidity cannot be determined from knowing the dewpoint alone, the actual air temperature must also be known. semiarid; warm winters and hot summers. Humidity is also measured on a global scale using remotely placed satellites. Relative humidity (RH) (expressed as a percent) also measures water vapor, but RELATIVE to the temperature of the air. P This is the biggest non-radiative cooling effect at the surface. These examples show how relative humidity can be quite misleading. (a) Tundra. Some cases may possibly be related to respiratory conditions such as asthma, while others may be the product of anxiety. {\displaystyle \phi )} El Nino and La Nina This effect can be calculated using a heat index table, also known as a humidex. Density altitude is the altitude relative to the standard atmosphere conditions (International Standard Atmosphere) at which the air density would be equal to the indicated air density at the place of observation, or, in other words, the height when measured in terms of the density of the air rather than the distance from the ground. Which statement best explains the difference between the cities' climates? Darwin experiences an extremely humid wet season from December to April. Also, if the atmosphere is as warm or warmer than the skin during times of high humidity, blood brought to the body surface cannot dissipate heat by conduction to the air. Relative humidity is also a key metric used to evaluate when it is appropriate to install flooring over a concrete slab. Sci. Humidity plays an important role for surface life. There are two main seasons in a tropical marine climate: the wet season and the dry season. It forms at low latitudes, generally within 25 degrees of the equator. The air is able to pick up water from the ocean, the water in the air makes it more A particular danger to electronic items, regardless of the stated operating humidity range, is condensation. Without other greenhouse gases, Earth's blackbody temperature, below the freezing point of water, would cause water vapor to be removed from the atmosphere. A humidistat is a humidity-triggered switch, often used to control a dehumidifier. Apart from spurious erratic function, electrostatic discharges can cause dielectric breakdown in solid-state devices, resulting in irreversible damage. Absolute and specific humidity are quite similar in concept. A major source of water vapor in Kentucky is the Gulf of Mexico. ten hottest places on earth (highest average monthly temperature) describes the temperature measured both in degrees Celsius and Fahrenheit as well the month of the year for selected countries with climate extremes. Air Masses and Fronts. Absolute humidity is the mass of the water vapor evaporate into a liquid. Because it's nearer to a body of water? Units should always be carefully checked. Theres a good reason why city dwellers flee to the countryside to cool off in the heat of summer: Rural areas are usually not as hot. In hot summer weather, a rise in relative humidity increases the apparent temperature to humans (and other animals) by hindering the evaporation of perspiration from the skin. Items of Interest As a condensible greenhouse gas, it precipitates, with a much lower scale height and shorter atmospheric lifetime weeks instead of decades. At 100% relative humidity, air is saturated and at its dew point: the water vapor pressure would permit neither evaporation of nearby liquid water nor condensation to grow the nearby water; neither sublimation of nearby ice nor deposition to grow the nearby ice. In many places, the Costa Rica climate is warm and damp for half the year. When an electronic item is moved from a cold place (e.g., garage, car, shed, air conditioned space in the tropics) to a warm humid place (house, outside tropics), condensation may coat circuit boards and other insulators, leading to short circuit inside the equipment. Daily Temp/Precip Maps Therefore, when applying more pressure to a gas saturated with water, all components will initially decrease in volume approximately according to the ideal gas law. Mists, clouds, fogs and aerosols of water do not count towards the measure of relative humidity of the air, although their presence is an indication that a body of air may be close to the dew point. Similarly, during summer in humid climates a great deal of liquid water condenses from air cooled in air conditioners. Another 21% of the molecules in dry air are oxygen (O2). The amount of water vapor contained within a parcel of air can vary significantly. On this Wikipedia the language links are at the top of the page across from the article title. In addition, temperature, relative humidity, precipitation, sunlight hours, and wind speed were important meteorological indexes affecting vibriosis that lag by 3, 8, 8, 2, and 11 weeks, respectively. Much of Costa Rica fits this description perfectly. Such short circuits may cause substantial permanent damage if the equipment is powered on before the condensation has evaporated. Sukkur city located on the Indus River in Pakistan has some of the highest and most uncomfortable dew points in the country, frequently exceeding 30C (86F) in the monsoon season.[23]. For example, a parcel of air near saturation may contain 28 g of water per cubic metre of air at 30C (86F), but only 8 g of water per cubic metre of air at 8C (46F). However, it absorbs the infrared energy emitted (radiated) upward by the earth's surface, which is the reason that humid areas experience very little nocturnal cooling but dry desert regions cool considerably at night. is the absolute pressure expressed in millibars, and 1-Stop Drought ) WebThe air near the center of this low-pressure system usually will. Although humidity is an important factor for thermal comfort, humans are more sensitive to variations in temperature than they are to changes in relative humidity. Normally our weather, notably rain, comes from the oceans. The sun heats ocean waters causing warm water to rise. As this warm water rises it pushe In addition, there may be safety considerations. Local Climate Pages Naturally aspirated internal combustion engines have a further danger of ice forming inside the carburetor. [38], Very low humidity can create discomfort, respiratory problems, and aggravate allergies in some individuals. Because of the potential confusion, British Standard BS 1339 [10] suggests avoiding the term "absolute humidity". Bangkok, Ho Chi Minh City, Kuala Lumpur, Hong Kong, Manila, Jakarta, Naha, Singapore, Kaohsiung and Taipei have very high humidity most or all year round because of their proximity to water bodies and the equator and often overcast weather. Bouvet Island. (These are analogous to a thermometer and thermostat for temperature, respectively.). is the equilibrium vapor pressure expressed in millibars. e {\displaystyle (p_{s})} Liquid water evaporates from oceans, lakes, rivers, plants, the ground, and fallen rain. Answer. As such, Relative humidity only considers the invisible water vapour. WebSea level rises at about 2.3 millimeters (0.2 inch) every year, contributing to up to 900% more frequent flooding in coastal areas. WebIn the peninsula of Baja California, practically a continuation of California, the climate is very mild on the west coast, where daytime temperatures range from 19/20 degrees Celsius (66/68 F) in winter to 24/25 C (75/77 F) in summer in the northern part. [37], Some people experience difficulty breathing in humid environments. Water vapor specifically absorbs and re-radiates radiation in this spectral band. To me, there is a huge difference between a hot and humid day, and a hot and dry day. I strongly prefer hot and dry. So much so that during my care Question 2. Each atmospheric gas has its own vapor pressure, a measure of the In the Wilson cloud chamber, which is used in nuclear physics experiments, a state of supersaturation is created within the chamber, and moving subatomic particles act as condensation nuclei so trails of fog show the paths of those particles. Meteorologists routinely consider the "dewpoint" temperature (instead of, but analogous to absolute humidity) to evaluate moisture, especially in the spring and summer. 2 WebNorthern Mexico. Outside the monsoon seasons, humidity is high (in comparison to countries further from the Equator), but completely sunny days abound. Do we conserve or release water as the climate changes? WebAnother change that takes place with the passage of the sea breeze front is an increase in humidity. WebIn geography, the temperate climates of Earth occur in the middle latitudes (23.5 to 66.5 N/S of Equator), which span between the tropics and the polar regions of Earth. ) Decision Support Page Even with saturation (100% relative humidity) outdoors, heating of infiltrated outside air that comes indoors raises its moisture capacity, which lowers relative humidity and increases evaporation rates from moist surfaces indoors (including human bodies and household plants.). Air mass is the meteorological term for a volume of air with a constant temperature and humidity covering an area. The low humidity is a consequence of drawing in the very cold air with a low absolute humidity, which is found at airliner cruising altitudes. ASHRAE Standard 160 (2016). Rather than the spring, summer, fall, and winter pattern found in more temperate areas. Equatorial (E): Equatorial air is hot and originates along 0 degrees (the equator). [55], High humidity in the oven, represented by an elevated wet-bulb temperature, increases the thermal conductivity of the air around the baked item, leading to a quicker baking process or even burning. WebThe rainiest month is August, with 100 mm (4 in) on average. (d) Tropical Evergreen. ) in drying, where temperature can vary considerably. From what I hear, as the Gulf (the body of water than impacts my area of the country, as it heats in the late spring and summer, a high pressure an antarctic. or For example, because humidity reduces ambient oxygen concentrations (dry air is typically 20.9% oxygen, but at 100% relative humidity the air is 20.4% oxygen), flue gas fans must intake air at a higher rate than would otherwise be required to maintain the same firing rate. This is shown in State B. A related parameter is the dew point. [36] In general, higher temperatures will require lower humidities to achieve thermal comfort compared to lower temperatures, with all other factors held constant. {\displaystyle (p)} 2 (b)).Salt fogs are absorbed by an Relative humidity increases as well, going from 33% in June, to 55% in July, and to 51% in August and September, thus making the heat sweltering. During the summer months the average temperature lies at 35 C during the day, dropping to about 20 C at night. WebThe areas most at risk are the coastal ones because of storm surges coming from the sea. be warmer. ( (The addition of water molecules, or any other molecules, to a gas, without removal of an equal number of other molecules, will necessarily require a change in temperature, pressure, or total volume; that is, a change in at least one of these three parameters. Central U.S. NWS WebA huge volume of air covering thousands of square kilometers that has relatively uniform temperature and water vapor concentration (humidity) horizontally. The field concerned with the study of physical and thermodynamic properties of gasvapor mixtures is named psychrometrics. WebHigh-pressure areas usually are areas of fair, settled weather. The recommended environmental qualifications for most commercial aircraft components is listed in RTCA DO-160. This explains the low levels (in the absence of measures to add moisture) of humidity in heated structures during winter, resulting in dry skin, itchy eyes, and persistence of static electric charges. The Etesians/ Meltemi The strong northerly winds which blow at times over the Aegean Sea and eastern parts of the Mediterranean Sea during the period May to October. 1997. It forms poleward of 60 degrees N/S. Humans can be comfortable within a wide range of humidities depending on the temperaturefrom 30 to 70%[33]but ideally not above the Absolute (60F Dew Point),[34] between 40%[35] and 60%. , which can be expressed as: The absolute humidity changes as air temperature or pressure changes, if the volume is not fixed. This causes air to rise, producing clouds and condensation. Relative Humidity is the ratio of the amount of water vapor, i.e., gaseous water, present in the air compared to the maximum amount of water vapor Warming some air containing a fog may cause that fog to evaporate, as the air between the water droplets becomes more able to hold water vapour. Part I: A Temperature-Humidity Index Based on Human Physiology and Clothing Science", 10.1175/1520-0450(1979)018<0861:TAOSPI>2.0.CO;2, "Climate/humidity table Transport Informations Service", "What is atmospheric humidity and how is it measured? [42] Indoor relative humidities should be kept above 30% to reduce the likelihood of the occupant's nasal passages drying out, especially in winter. Humidity is the concentration of water vapor present in the air. Easy answer, partner. Q. How humid is Texas? A. Go to your bathroom, start the shower, and close the door. Turn on the hot water only and let it Calibration standards for the most accurate measurement include the gravimetric hygrometer, chilled mirror hygrometer, and electrolytic hygrometer. Brazil. ten coldest places on earth (lowest average monthly temperature) describes temperature measured in both degrees Celsius and Fahrenheit as well as the month of the year for selected countries with climate extremes. Long-term average salt-fog concentrations are determined through the placement of an absorption device directly in the environment of interest, where ambient air is pumped at a constant flow rate of 0.8 L/min (Fig. At this point, the storm has typically weakened, but it can still cause damage. Baker, Howland, and Jarvis Islands: equatorial; scant rainfall, constant wind, burning sun; Johnston Atoll and Kingman Reef: tropical, but generally dry; consistent northeast trade winds with little seasonal temperature variation; Midway Islands: subtropical with cool, moist winters (December to February) and warm, dry summers (May to October); moderated by prevailing easterly winds; most of the 107 cm of annual rainfall occurs during the winter; Palmyra Atoll: equatorial, hot; located within the low pressure area of the Intertropical Convergence Zone (ITCZ) where the northeast and southeast trade winds meet, it is extremely wet with between 400-500 cm of rainfall each year, warm temperate; freezing temperatures almost unknown, mostly mid-latitude desert, long, hot summers, mild winters; semiarid grassland in east, tropical; moderated by southeast trade winds from May to October; moderate rainfall from November to April; may be affected by cyclones from December to April, tropical in south; monsoonal in north with hot, rainy season (May to September) and warm, dry season (October to March), subtropical, tempered by easterly trade winds, relatively low humidity, little seasonal temperature variation; rainy season September to November, tropical; hot, rainy season (November to April); cool, dry season (May to October); rains 250-300 cm per year (80% humidity); average temperature 26.6 degrees Celsius, temperate; temperature and precipitation vary with altitude, warm to hot summers, cool to mild winters, a wide equatorial band of hot and humid tropical climates, bordered north and south by subtropical temperate zones that separate two large areas of cold and dry polar climatesten driest places on earth (average annual precipitation): McMurdo Dry Valleys, Antarctica 0 mm (0 in)Arica, Chile 0.76 mm (0.03 in)Al Kufrah, Libya 0.86 mm (0.03 in)Aswan, Egypt 0.86 mm (0.03 in)Luxor, Egypt 0.86 mm (0.03 in)Ica, Peru 2.29 mm (0.09 in)Wadi Halfa, Sudan 2.45 mm (0.1 in)Iquique, Chile 5.08 mm (0.2 in)Pelican Point, Namibia 8.13 mm (0.32 in)El Arab (Aoulef), Algeria 12.19 mm (0.48 in)ten wettest places on earth (average annual precipitation): Mawsynram, India 11,871 mm (467.4 in)Cherrapunji, India 11,777 mm (463.7 in)Tutunendo, Colombia 11,770 mm (463.4 in)Cropp River, New Zealand 11,516 mm (453.4 in)San Antonia de Ureca, Equatorial Guinea 10,450 mm (411.4 in)Debundsha, Cameroon 10,299 mm (405.5 in)Big Bog, US (Hawaii) 10,272 mm (404.4 in)Mt Waialeale, US (Hawaii) 9,763 mm (384.4 in)Kukui, US (Hawaii) 9,293 mm (365.9 in)Emeishan, China 8,169 mm (321.6 in)ten coldest places on earth (lowest average monthly temperature): Verkhoyansk, Russia (Siberia) -47C (-53F) JanuaryOymyakon, Russia (Siberia) -46C (-52F) JanuaryEureka, Canada -38.4C (-37.1F) FebruaryIsachsen, Canada -36C (-32.8F) FebruaryAlert, Canada -34C (-28F) FebruaryKap Morris Jesup, Greenland -34C (-29F) MarchCornwallis Island, Canada -33.5C (-28.3F) FebruaryCambridge Bay, Canada -33.5C (28.3F) FebruaryIlirnej, Russia -33C (-28F) JanuaryResolute, Canada -33C (-27.4F) Februaryten hottest places on earth (highest average monthly temperature): Death Valley, US (California) 39C (101F) JulyIranshahr, Iran 38.3C (100.9F) June Ouallene, Algeria 38C (100.4F) JulyKuwait City, Kuwait 37.7C (100F) JulyMedina, Saudi Arabia 36C (97F) JulyBuckeye, US (Arizona) 34C (93F) JulyJazan, Saudi Arabia 33C (91F) JuneAl Kufrah, Libya 31C (87F) JulyAlice Springs, Australia 29C (84F) JanuaryTamanrasset, Algeria 29C (84F) June, mostly desert; hot and humid along west coast; temperate in western mountains affected by seasonal monsoon; extraordinarily hot, dry, harsh desert in east, tropical; modified by altitude; rainy season (October to April), tropical; moderated by altitude; rainy season (November to March), Saint Helena, Ascension, and Tristan da Cunha, United States Pacific Island Wildlife Refuges, Center for the Study of Intelligence (CSI). In vehicles and pressure vessels such as pressurized airliners, submersibles and spacecraft, these considerations may be critical to safety, and complex environmental control systems including equipment to maintain pressure are needed. Torrential rains from the storm can cause rivers to flood their banks and mudslides to form. be more dry. , divided by the volume of the air and water vapor mixture H A good example is the Atacama of Chile. Generally, the closer to the ocean the more moisture enters the air, but not always. If there is a sea breeze that is yrue, if its a land breeze ch For fast and very accurate measurement the chilled mirror method is effective. ) Please select one of the following: Experimental Graphical Hazardous Weather Outlook, National Oceanic and Atmospheric Administration. This is a mechanism behind thunderstorms and other weather phenomena. ( Pilots must take humidity into account when calculating takeoff distances, because high humidity requires longer runways and will decrease climb performance. Multiple locations were found. The detection rate of V. parahaemolyticus was significantly higher in the eastern coastal areas and northwest compared with the southwest. It does not take temperature into consideration. WebThe amount of watervapour present in the atmosphere determines the humidity of a place The humidity in coastal areas is usually greaterthan that of the inland areas When the temperature is low and the relative humidity is high, evaporation of water is slow. WebThe word that describes humidity (maritime or continental) is paired with the word that describes temperature (equatorial, tropical, polar or arctic). Ile Amsterdam et Ile Saint-Paul: oceanic with persistent westerly winds and high humidity; Iles Crozet: windy, cold, wet, and cloudy; Iles Kerguelen: oceanic, cold, overcast, windy; tropical; hot, rainy season (June to November); cooler, dry season (November to May), temperate, mild winters, dry and warm to hot summers, warm and pleasant; Mediterranean-like on Black Sea coast, temperate and marine; cool, cloudy, wet winters and summers; occasional warm mountain (foehn) wind, tropical; warm and comparatively dry along southeast coast; hot and humid in southwest; hot and dry in north, Mediterranean with mild winters and warm summers, temperate; mild, wet winters; hot, dry summers, arctic to subarctic; cool summers, cold winters, tropical; tempered by northeast trade winds, tropical marine; generally warm and humid, moderated by northeast trade winds; dry season (January to June), rainy season (July to December); little seasonal temperature variation, tropical; hot, humid in lowlands; cooler in highlands, temperate with mild winters and cool summers; about 50% of days are overcast, generally hot and humid; monsoonal-type rainy season (June to November) with southwesterly winds; dry season (December to May) with northeasterly harmattan winds, tropical; generally hot and humid; monsoonal-type rainy season (June to November) with southwesterly winds; dry season (December to May) with northeasterly harmattan winds, tropical; hot, humid, moderated by northeast trade winds; two rainy seasons (May to August, November to January), tropical; semiarid where mountains in east cut off trade winds, temperate; mild, rainy winters (September to May) with hot, dry summers (May to September), subtropical in lowlands, temperate in mountains, subtropical monsoon; cool and humid in winter, hot and rainy from spring through summer, warm and sunny in fall, temperate; cold, cloudy, humid winters; warm summers, temperate; moderated by North Atlantic Current; mild, windy winters; damp, cool summers, varies from tropical monsoon in south to temperate in north, northeast monsoon (December to April), southwest monsoon (June to October); tropical cyclones occur during May/June and October/November in the northern Indian Ocean and January/February in the southern Indian Ocean, tropical; hot, humid; more moderate in highlands, mostly arid or semiarid, subtropical along Caspian coast, mostly desert; mild to cool winters with dry, hot, cloudless summers; northern mountainous regions along Iranian and Turkish borders experience cold winters with occasionally heavy snows that melt in early spring, sometimes causing extensive flooding in central and southern Iraq, temperate maritime; modified by North Atlantic Current; mild winters, cool summers; consistently humid; overcast about half the time, temperate; cool summers and mild winters; overcast about a third of the time, temperate; hot and dry in southern and eastern desert areas, predominantly Mediterranean; alpine in far north; hot, dry in south, arctic maritime with frequent storms and persistent fog, varies from tropical in south to cool temperate in north, mostly arid desert; rainy season in west (November to April), continental, cold winters and hot summers, arid and semiarid, varies from tropical along coast to arid in interior, tropical; marine, hot and humid, moderated by trade winds, temperate, with rainfall concentrated in summer; long, bitter winters, temperate, with rainfall heavier in summer than winter; cold winters, influenced by continental air masses resulting in relatively cold winters with heavy snowfall and hot, dry summers and autumns; Mediterranean and alpine influences create regional variation; maximum rainfall between October and December, dry desert; intensely hot summers; short, cool winters, dry continental to polar in high Tien Shan Mountains; subtropical in southwest (Fergana Valley); temperate in northern foothill zone, tropical monsoon; rainy season (May to November); dry season (December to April), Mediterranean; mild to cool, wet winters with hot, dry summers; the Lebanon Mountains experience heavy winter snows, temperate; cool to cold, dry winters; hot, wet summers, tropical; hot, humid; dry winters with hot days and cool to cold nights; wet, cloudy summers with frequent heavy showers, Mediterranean along coast; dry, extreme desert interior, continental; cold, cloudy winters with frequent snow or rain; cool to moderately warm, cloudy, humid summers, transitional, between maritime and continental; wet, moderate winters and summers, modified continental with mild winters, cool summers, subtropical; marine with cool winters, warm summers, tropical along coast, temperate inland, arid in south, sub-tropical; rainy season (November to May); dry season (May to November), tropical; annual southwest (April to October) and northeast (October to February) monsoons, tropical; hot, humid; dry, northeast monsoon (November to March); rainy, southwest monsoon (June to August), subtropical to arid; hot and dry (February to June); rainy, humid, and mild (June to November); cool and dry (November to February), Mediterranean; mild, rainy winters; hot, dry summers, tropical; hot and humid; wet season May to November; islands border typhoon belt, tropical, modified by southeast trade winds; warm, dry winter (May to November); hot, wet, humid summer (November to May), tropical; heavy year-round rainfall, especially in the eastern islands; located on southern edge of the typhoon belt with occasionally severe damage, Mediterranean with mild, wet winters and hot, dry summers, desert; continental (large daily and seasonal temperature ranges), Mediterranean climate, hot dry summers and autumns and relatively cold winters with heavy snowfalls inland, tropical; little daily or seasonal temperature variation, Mediterranean in the north, becoming more extreme in the interior; in the south, hot, dry desert; rain is rare; cold offshore air currents produce fog and heavy dewnote: data does not include former Western Sahara, desert; hot, dry; rainfall sparse and erratic, tropical with a monsoonal pattern; rainy season (November to February), varies from cool summers and severe winters in north to subtropical summers and mild winters in south, temperate; marine; cool summers and mild winters, tropical; modified by southeast trade winds; hot, humid, tropical in lowlands, cooler in highlands, desert; mostly hot, dry, dusty; tropical in extreme south, varies; equatorial in south, tropical in center, arid in north, tropical; modified by southeast trade winds, subtropical; mild, little seasonal temperature variation, warm, dry summers and autumns; relatively cold winters with heavy snowfall, tropical marine; moderated by northeast trade winds, little seasonal temperature variation; dry season December to June, rainy season July to October, temperate along coast, modified by North Atlantic Current; colder interior with increased precipitation and colder summers; rainy year-round on west coast, dry desert; hot, humid along coast; hot, dry interior; strong southwest summer monsoon (May to September) in far south, planetary air pressure systems and resultant wind patterns exhibit remarkable uniformity in the south and east; trade winds and westerly winds are well-developed patterns, modified by seasonal fluctuations; tropical cyclones (hurricanes) may form south of Mexico from June to October and affect Mexico and Central America; continental influences cause climatic uniformity to be much less pronounced in the eastern and western regions at the same latitude in the North Pacific Ocean; the western Pacific is monsoonal - a rainy season occurs during the summer months, when moisture-laden winds blow from the ocean over the land, and a dry season during the winter months, when dry winds blow from the Asian landmass back to the ocean; tropical cyclones (typhoons) may strike southeast and east Asia from May to December, mostly hot, dry desert; temperate in northwest; arctic in north, tropical; hot and humid; wet season May to November, tropical maritime; hot, humid, cloudy; prolonged rainy season (May to January), short dry season (January to May), tropical; northwest monsoon (December to March), southeast monsoon (May to October); slight seasonal temperature variation, subtropical to temperate; substantial rainfall in the eastern portions, becoming semiarid in the far west, varies from tropical in east to dry desert in west; temperate to frigid in Andes, tropical marine; northeast monsoon (November to April); southwest monsoon (May to October), tropical; hot and humid; modified by southeast trade winds; rainy season (November to March), temperate with cold, cloudy, moderately severe winters with frequent precipitation; mild summers with frequent showers and thundershowers, maritime temperate; cool and rainy in north, warmer and drier in south, tropical marine, mild; little seasonal temperature variation, temperate; cold, cloudy winters with frequent snow and fog; sunny summers with frequent showers and thunderstorms, ranges from steppes in the south through humid continental in much of European Russia; subarctic in Siberia to tundra climate in the polar north; winters vary from cool along Black Sea coast to frigid in Siberia; summers vary from warm in the steppes to cool along Arctic coast, temperate; two rainy seasons (February to April, November to January); mild in mountains with frost and snow possible, tropical, with practically no variation in temperature; has two seasons (dry and humid).