CLIMATE


climate--the aggregate weather conditions; includes averages and extremes

microclimate--climate of a small area

Köppen System

based on mean annual and monthly values of temperature and precipitation

4 of 6 groups by temperature; 5th by moisture; 6th by topography

climatic diagram or climagraph--shows monthly temperature, precipitation; range; location

A--humid tropical [tropical]--winterless--average above 64.4°F (18°C)--Brazil; central America; southern half of Africa excluding the tip; India to Indonesia; Madagascar; largest area

1) tropical wet (Af) [tropical rainforest]--hot humid wet all year-- > 2.4" (6 cm) per month;--(northern Brazil, Central America, Indonesia; middle of Africa)
2) tropical monsoonal (Am) [tropical wet and dry]--short dry season, very wet rainy season with high concentration in a few months--at least one month under 2.4" (6 cm)--(west coast India,Burma, Thailand, other coasts)
3) tropical savannah (Aw) [tropical wet and dry]--hot, humid but dry season in winter and longer;--at least one month under 2.4" (6 cm)--most extensive A climate--(southern Brazil; central Africa, southern Asia, northern Australia; Middle America; Cuba)

B--arid--dry-water deficient--30% land area of earth; subtropical high pressure zone; continental or topographic barriers;--western United States; northern Chile; southeastern Argentina; Kalahari; Sahara, Saudi Arabia; southern former U.S.S.R.; central Australia

4) desert (Bw)-more evaporation than precipitation
(a) low latitude desert (BWh) [subtropical, low latitude dry]--between 0 and 15" precipitation average annual temperature is over 64.4°F (18°C); (Atacama; Sahara, central Australia)
(b) midlatitude desert (BWk) [mid-latitude dry]--between 0 and 10" precipitation and average temperature under 64.4°F--(Asia; southwestern U.S.; southern Argentina)
5) steppe (semiarid) (Bs)--more vegetation and precipitation
(a) low latitude steppe (BSh) [subtropical, low latitude dry]--between 15 and 30" precipitation and average annual temperature over 64.4°F (18°C)--surround subtropical deserts
(b) midlatitude steppe (BSk) [mid-latitude dry]--between 10 and 20" precipitation and average annual temperature under 64.4°F (18°C)--(southwestern United States)
C--mild middle-latitude [mesothermal, mild winter (meso means middle)]--mild winters; humid; warmest month averages above 50°F (10°C) but coldest is above 32°F (0°C) and below 64.4°F (18°C)--southeastern United States; west coast United States; Europe; southeastern China

6) humid subtropical (Cfa, Cwa)--hot summer, mild winter; may be dry winter; warmest month averages above 71.6°F (22°C) and coldest month averages less than 64.4°F (18°C) but greater than 32°F (0°C)--(southeastern United States; China)
7) marine west coast (Cfb, Cfc) [marine]--ocean current moderates, mild summer and winter; warmest month averages below 71.6°F (22°C) and coldest month averages less than 64.4°F (18°C) but greater than 32°F (0°C)--poleward from mediterranean climate; (west and central Europe; New Zealand; Washington and Oregon coast)
8) mediterranean (Csa, Csb) [dry summer subtropical]--warm, dry summer, mild, moist winter or hot summer has drought, winter precipitation but not freezing; sometimes known as dry (summer) subtropical; coldest month averages less than 64.4°F (18°C) but greater than 32°F (0°C) difference is the summer drought--(California; Chile; Mediterranean; tip Africa and Australia)

D--severe middle-latitude [microthermal, severe winter]--severe winters; humid; at least one month averages below 32°F (0°C) and warmest month averages above 50°F (10°C)--northern North America; northern Asia--CONTINENTALITY

9) humid continental (Dfa, Dfb, Dwa, Dwb)--cold winter, warm summer, precipitation all year; at least four months average over 50°F (10°C) and coldest month averages below 32°F (0°C)--(northeastern quarter of United States; triangle of Moscow)
10) subarctic (Dfc, Dfd, Dwc, Dwd)--cold and snow, three or less months average over 50°F (10°C)--WINTER--taiga, boreal; GREATEST RANGE; (Canada; Siberia)

E--polar--summerless (humid: little evaporation); no month averages over 50°F (10°C); treeless--Greenland; northern tip of continents in northern hemisphere; Antarctica

11) tundra (ET)--cold, low-growing shrubs and herbs; one month averages above 32°F (0°C) but less than 50°F (10°C); but all average below 50°F--TREE LINE; permafrost
12) ice cap (EF)--all months average below 32°F (0°C); ice and snow covered--(Greenland, Antarctica)

F--highland, influence by vertical zonation--temperatures, precipitation, vegetation changes with elevation on a mountain

13) highland (H or F)--altitude, exposure (sun and wind), CHANGABILITY--(Andes; Rockies; Alps; Himalayas)

Go to the climate review questions

Go to the climate map

Go to the hypothetical continent climate map

Dr. M. H. Hill's Homepage