Worldwide zones of Tropical savanna climate (Aw/As)

Tropical savanna climate or tropical wet and dry climate is a tropical climate sub-type that corresponds to the Köppen climate classification categories Aw (for a dry "winter") and As (for a dry "summer"). The driest month has less than 60 mm (2.4 in) of precipitation and also less than mm of precipitation.[1]: 200–1 

This latter fact is in a direct contrast to a tropical monsoon climate, whose driest month sees less than 60 mm (2.4 in) of precipitation but has more than of precipitation. In essence, a tropical savanna climate tends to either see less overall rainfall than a tropical monsoon climate or have more pronounced dry season(s). It is impossible for a tropical savanna climate to have more than 2,500 mm (98 in) as such would result in a negative value in that equation.

In tropical savanna climates, the dry season can become severe, and often drought conditions prevail during the course of the year. Tropical savanna climates often feature tree-studded grasslands due to its dryness, rather than thick jungle. It is this widespread occurrence of tall, coarse grass (called savanna) which has led to Aw and As climates often being referred to as the tropical savanna. However, there is some doubt whether tropical grasslands are climatically induced. Additionally, pure savannas, without trees, are the exception rather than the rule.

Versions

There are generally four types of tropical savanna climates:

Distribution

Dry forest in Thailand
Savanna in South Sudan

Tropical savanna climates are most commonly found in Africa, Asia, and South America. The climate is also prevalent in sections of Central America, northern Australia, the Pacific Islands, in extreme southern North America in south Florida, and some islands in the Caribbean. Most places that have this climate are found at the outer margins of the tropical zone, but occasionally an inner-tropical location (e.g., San Marcos, Antioquia, Colombia) also qualifies. Similarly, the Caribbean coast, eastward from the Gulf of Urabá on the ColombiaPanamá border to the Orinoco river delta, on the Atlantic Ocean (ca. 4,000 km (2,485 mi)), have long dry periods (the extreme is the BSh climate (see below), characterized by very low, unreliable precipitation, present, for instance, in extensive areas in the Guajira, and Coro, western Venezuela, the northernmost peninsulas in South America, which receive <300 mm (11.8 in) total annual precipitation, practically all in two or three months). This condition extends to the Lesser Antilles and Greater Antilles forming the Circumcaribbean dry belt. The length and severity of the dry season diminishes inland (southward); at the latitude of the Amazon river—which flows eastward, just south of the equatorial line—the climate is Af. East from the Andes, between the arid Caribbean and the ever-wet Amazon, are the Orinoco river Llanos or savannas, from where this climate takes its name.

Sometimes As is used in place of Aw if the dry season occurs during the time of higher sun and longer days. This is typically due to a rain shadow effect that cuts off ITCZ-triggered summer precipitation in a tropical area while winter precipitation remains sufficient to preclude a BSh semi-arid classification (or when the warmest month occurs during the winter dry season). This is the case in East Africa (Mombasa, Kenya, Somalia), Sri Lanka (Trincomalee) and coastal regions of Northeastern Brazil (from São Luís[2] through Natal to Maceió), for instance. The difference between "summer" and "winter" in such tropical locations is usually so slight that a distinction between an As and Aw climate is a quibble. In most places that have tropical wet and dry climates, however, the dry season occurs during the time of lower sun and shorter days because of reduction of or lack of convection, which in turn is due to the meridional shifts of the Intertropical Convergence Zone during the entire course of the year, based on which hemisphere the location sits.

Cities with a tropical savanna climate

Some examples of tropical savanna climates[edit]

Banjul, The Gambia
Climate chart (explanation)
J
F
M
A
M
J
J
A
S
O
N
D
 
 
0.5
 
 
32
16
 
 
0
 
 
34
17
 
 
0
 
 
34
18
 
 
0
 
 
33
19
 
 
1.3
 
 
32
20
 
 
63
 
 
32
23
 
 
232
 
 
31
24
 
 
347
 
 
30
23
 
 
255
 
 
31
23
 
 
76
 
 
32
22
 
 
1.6
 
 
33
19
 
 
0.7
 
 
32
16
Average max. and min. temperatures in °C
Precipitation totals in mm
Source: BBC Weather[3]
Imperial conversion
JFMAMJJASOND
 
 
0
 
 
89
60
 
 
0
 
 
92
62
 
 
0
 
 
93
64
 
 
0
 
 
91
66
 
 
0.1
 
 
89
69
 
 
2.5
 
 
89
73
 
 
9.1
 
 
87
74
 
 
14
 
 
86
74
 
 
10
 
 
88
73
 
 
3
 
 
89
72
 
 
0.1
 
 
91
66
 
 
0
 
 
89
61
Average max. and min. temperatures in °F
Precipitation totals in inches
Monte Cristi, Dominican Republic
Climate chart (explanation)
J
F
M
A
M
J
J
A
S
O
N
D
 
 
74
 
 
29
19
 
 
47
 
 
29
20
 
 
48
 
 
30
20
 
 
59
 
 
31
21
 
 
60
 
 
32
22
 
 
40
 
 
33
23
 
 
22
 
 
34
23
 
 
28
 
 
34
23
 
 
35
 
 
34
23
 
 
68
 
 
33
22
 
 
108
 
 
31
21
 
 
84
 
 
29
20
Average max. and min. temperatures in °C
Precipitation totals in mm
Source: NOAA[4]
Imperial conversion
JFMAMJJASOND
 
 
2.9
 
 
84
67
 
 
1.9
 
 
85
67
 
 
1.9
 
 
86
68
 
 
2.3
 
 
87
70
 
 
2.4
 
 
89
72
 
 
1.6
 
 
92
73
 
 
0.8
 
 
92
74
 
 
1.1
 
 
93
74
 
 
1.4
 
 
93
73
 
 
2.7
 
 
91
72
 
 
4.3
 
 
87
70
 
 
3.3
 
 
85
68
Average max. and min. temperatures in °F
Precipitation totals in inches
Brasília, Brazil
Climate chart (explanation)
J
F
M
A
M
J
J
A
S
O
N
D
 
 
241
 
 
27
17
 
 
215
 
 
27
17
 
 
189
 
 
27
18
 
 
124
 
 
27
17
 
 
39
 
 
26
15
 
 
8.8
 
 
25
13
 
 
12
 
 
25
13
 
 
13
 
 
27
15
 
 
52
 
 
28
16
 
 
172
 
 
28
17
 
 
238
 
 
27
18
 
 
249
 
 
26
18
Average max. and min. temperatures in °C
Precipitation totals in mm
Source: World Weather Information Service [1]
Imperial conversion
JFMAMJJASOND
 
 
9.5
 
 
80
63
 
 
8.5
 
 
80
63
 
 
7.4
 
 
81
64
 
 
4.9
 
 
80
62
 
 
1.5
 
 
78
59
 
 
0.3
 
 
77
56
 
 
0.5
 
 
77
55
 
 
0.5
 
 
81
58
 
 
2
 
 
83
61
 
 
6.8
 
 
82
63
 
 
9.4
 
 
80
64
 
 
9.8
 
 
79
64
Average max. and min. temperatures in °F
Precipitation totals in inches
Darwin, Australia
Climate chart (explanation)
J
F
M
A
M
J
J
A
S
O
N
D
 
 
466
 
 
32
25
 
 
373
 
 
32
25
 
 
335
 
 
32
25
 
 
108
 
 
33
24
 
 
25
 
 
32
23
 
 
2.3
 
 
31
20
 
 
1.2
 
 
31
20
 
 
5.8
 
 
32
20
 
 
18
 
 
33
23
 
 
65
 
 
34
25
 
 
137
 
 
34
26
 
 
276
 
 
33
26
Average max. and min. temperatures in °C
Precipitation totals in mm
Source: Australian Bureau of Meteorology [2]
Imperial conversion
JFMAMJJASOND
 
 
18
 
 
89
77
 
 
15
 
 
89
77
 
 
13
 
 
90
76
 
 
4.2
 
 
91
76
 
 
1
 
 
90
73
 
 
0.1
 
 
87
68
 
 
0
 
 
87
67
 
 
0.2
 
 
89
69
 
 
0.7
 
 
91
74
 
 
2.6
 
 
92
77
 
 
5.4
 
 
92
78
 
 
11
 
 
91
78
Average max. and min. temperatures in °F
Precipitation totals in inches
Tegucigalpa, Honduras
Climate chart (explanation)
J
F
M
A
M
J
J
A
S
O
N
D
 
 
5.3
 
 
26
14
 
 
4.7
 
 
27
15
 
 
9.9
 
 
30
16
 
 
43
 
 
30
17
 
 
144
 
 
30
18
 
 
159
 
 
29
18
 
 
82
 
 
28
18
 
 
89
 
 
29
18
 
 
177
 
 
29
18
 
 
109
 
 
27
18
 
 
40
 
 
26
16
 
 
9.9
 
 
25
15
Average max. and min. temperatures in °C
Precipitation totals in mm
Source: WMO[5]
Imperial conversion
JFMAMJJASOND
 
 
0.2
 
 
78
58
 
 
0.2
 
 
81
58
 
 
0.4
 
 
85
60
 
 
1.7
 
 
86
63
 
 
5.6
 
 
86
65
 
 
6.2
 
 
83
65
 
 
3.2
 
 
82
64
 
 
3.5
 
 
83
64
 
 
7
 
 
83
64
 
 
4.3
 
 
81
64
 
 
1.6
 
 
79
61
 
 
0.4
 
 
78
59
Average max. and min. temperatures in °F
Precipitation totals in inches
Ho Chi Minh City, Vietnam
Climate chart (explanation)
J
F
M
A
M
J
J
A
S
O
N
D
 
 
14
 
 
32
21
 
 
4.1
 
 
33
23
 
 
11
 
 
34
24
 
 
50
 
 
35
26
 
 
218
 
 
34
25
 
 
312
 
 
32
25
 
 
294
 
 
32
24
 
 
270
 
 
32
24
 
 
327
 
 
31
24
 
 
267
 
 
31
24
 
 
117
 
 
31
23
 
 
48
 
 
31
21
Average max. and min. temperatures in °C
Precipitation totals in mm
Source: Vietnam Institute for Building Science and Technology [3]
Imperial conversion
JFMAMJJASOND
 
 
0.5
 
 
89
70
 
 
0.2
 
 
91
73
 
 
0.4
 
 
93
76
 
 
2
 
 
94
78
 
 
8.6
 
 
93
77
 
 
12
 
 
90
76
 
 
12
 
 
90
76
 
 
11
 
 
89
76
 
 
13
 
 
88
76
 
 
11
 
 
88
75
 
 
4.6
 
 
88
73
 
 
1.9
 
 
87
71
Average max. and min. temperatures in °F
Precipitation totals in inches

See also[edit]

References[edit]

  1. ^ 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. ^ Smart, Matthew P (2019). Thought, Action; Impact: Modes of Presentation to Enable an Immersive Reader-Response (Thesis). Queensland University of Technology. doi:10.5204/thesis.eprints.127474.
  3. ^ "World Weather Information Service — Banjul". Retrieved 3 March 2020.
  4. ^ "Station Name: MONTE CRISTI ... Country: DOMINICAN REPUBLIC". NOAA.
  5. ^ "Weather Information for Tegucigalpa, Country: HONDURAS". WMO.