Worldwide zones of tropical monsoon climate (Am).
Worldwide zones of tropical monsoon climate (Am).

An area of tropical monsoon climate (occasionally known as a tropical wet climate or a tropical monsoon and trade-wind littoral climate) is a type of climate that corresponds to the Köppen climate classification category subtype "Am". Tropical monsoon climates have monthly mean temperatures above 18 °C (64 °F) in every month of the year and a dry season.[1]: 200–1  Tropical monsoon climates is the intermediate climate between the wet Af (or tropical rainforest climate) and the drier Aw (or tropical savanna climate) in terms of dryness.

A tropical monsoon climate's driest month has on average less than 60 mm, but more than .[1] This is in direct contrast to the drier tropical savanna climate, whose driest month has less than 60 mm of precipitation and also less than of average monthly precipitation, as well as the wetter tropical rainforest climate with the driest month's rainfall above 60mm. In essence, a tropical monsoon climate tends to either have more rainfall than a tropical savanna climate or have less pronounced dry seasons, but still has a dry season unlike a tropical rainforest climate. A tropical monsoon climate tends to vary less in temperature during a year than does a tropical savanna climate because they are found closer to the equator. This climate has a driest month which nearly always occurs at or soon after the winter solstice, with monsoons normally giving precipitation in the summer instead .[1]

Versions

There are generally two versions of a tropical monsoon climate:

Distribution

Tropical monsoon are most commonly found in Africa (West and Central Africa), Asia (South and Southeast Asia), central of South America and Central America. This climate also occurs in sections of the Caribbean, North America, and northern Australia.

Factors

The major controlling factor over a tropical monsoon climate is its relationship to the monsoon circulation. The monsoon is a seasonal change in wind direction. In Asia, during the "summer" (or high-sun season) there is an onshore flow of air (air moving from ocean toward land) bringing oceanic precipitation. In the “winter” (or low-sun season) an offshore air flow (air moving from land toward water) is prevalent, drying the affected area. The change in direction is due to the difference in the way water and land heat and wind blows.

Changing pressure patterns that affect the seasonality of precipitation also occur in Africa though it generally differs from the way it operates in Asia. During the high-sun season, the Intertropical convergence zone (ITCZ) induces rain. During the low-sun season, the subtropical high creates dry conditions. The monsoon climates of Africa, and the Americas for that matter, are typically located along tradewind coasts, directly equatorward of tropical savanna climates.

Cities

Select charts[edit]

Chittagong
Climate chart (explanation)
J
F
M
A
M
J
J
A
S
O
N
D
 
 
5
 
 
27
15
 
 
28
 
 
30
19
 
 
64
 
 
35
24
 
 
150
 
 
39
26
 
 
264
 
 
35
24
 
 
533
 
 
34
25
 
 
597
 
 
38
26
 
 
518
 
 
33
24
 
 
320
 
 
33
24
 
 
180
 
 
32
23
 
 
56
 
 
32
17
 
 
15
 
 
24
14
Average max. and min. temperatures in °C
Precipitation totals in mm
Source: BBC[2]
Conakry
Climate chart (explanation)
J
F
M
A
M
J
J
A
S
O
N
D
 
 
1
 
 
32
19
 
 
1
 
 
33
20
 
 
3
 
 
33
21
 
 
22
 
 
34
22
 
 
137
 
 
33
21
 
 
396
 
 
32
20
 
 
1130
 
 
30
20
 
 
1104
 
 
30
21
 
 
617
 
 
31
21
 
 
295
 
 
31
20
 
 
70
 
 
32
21
 
 
8
 
 
32
20
Average max. and min. temperatures in °C
Precipitation totals in mm
Source: HK[3]
Manaus
Climate chart (explanation)
J
F
M
A
M
J
J
A
S
O
N
D
 
 
260
 
 
31
23
 
 
288
 
 
30
23
 
 
314
 
 
31
23
 
 
300
 
 
31
23
 
 
256
 
 
31
23
 
 
114
 
 
31
23
 
 
88
 
 
31
23
 
 
58
 
 
33
23
 
 
83
 
 
33
24
 
 
126
 
 
33
24
 
 
183
 
 
32
24
 
 
217
 
 
31
24
Average max. and min. temperatures in °C
Precipitation totals in mm
Source: WMO[4] HK[5]
Miami
Climate chart (explanation)
J
F
M
A
M
J
J
A
S
O
N
D
 
 
51
 
 
24
15
 
 
53
 
 
25
16
 
 
61
 
 
26
18
 
 
72
 
 
28
20
 
 
158
 
 
30
22
 
 
237
 
 
31
24
 
 
145
 
 
32
25
 
 
193
 
 
32
25
 
 
194
 
 
31
24
 
 
143
 
 
29
22
 
 
68
 
 
27
19
 
 
47
 
 
25
16
Average max. and min. temperatures in °C
Precipitation totals in mm
Source: WMO[6]

References[edit]

  1. ^ a b c McKnight, Tom L; Hess, Darrel (2000). "Climate Zones and Types". Physical Geography: A Landscape Appreciation. Upper Saddle River, New Jersey: Prentice Hall. ISBN 978-0-13-020263-5.
  2. ^ "Average Conditions - Chittagong, Bangladesh". BBC Weather. Archived from the original on 11 March 2006. Retrieved 25 June 2018.
  3. ^ "Climatological Normals of Conakry". Hong Kong Observatory. Retrieved 2014-02-12.
  4. ^ "Weather Information for Manaus". World Meteorological Organization. Retrieved 25 June 2018.
  5. ^ "Climatological Information for Manaus, Brazil". Hong Kong Observatory. 20 December 2012. Retrieved 25 June 2018.
  6. ^ "Weather Information for Miami, Florida". World Meteorological Organization. Retrieved 25 June 2018.