<p>Looking at equatorial Africa in Google Maps, the western part – Guinea, the Congo – is the dark green of tropical rain forest that I would expect of a wet equatorial region, by analogy with the Amazon basin and similar latitudes in east Asia.</p>
<p>By contrast, the eastern part – Kenya, Tanzania – is the light green of savanna and the light brown of semidesert or desert, indicating much drier conditions that at other longitudes, are more associated with the edges of the Hadley cells, 20-30 degrees away from the equator.</p>
<p>That's not at all the pattern I would've expected. By the basic logic of convection cells, plus analogy with other continents, I would've expected moist conditions across the width of equatorial Africa, but failing that, because the prevailing winds in the tropics blow from the east, I would've expected the eastern part of the continent (which gets wind from the Indian Ocean) to be wet and the western part (which gets wind that has blown some distance over land) to be drier.</p>
<p>Why is it that the western part of equatorial Africa is wet and the eastern part is dry?</p>
<p><a href="https://i.sstatic.net/ehETS.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ehETS.jpg" alt="enter image description here" /></a></p>

CC BY-SA 4.0
2021-08-31T16:44:55.430Z
Part of the answer probably has to do with topography: if you look at any topographic map of Africa (for instance here: https://commons.m.wikimedia.org/wiki/Category:DEM_maps_of_Africa), you'll see that Congo is in the lowlands, while Kenya and Tanzania are mountainous. Elevation has an impact on temperature and thus on vegetation.
Jean-Marie Prival
CC BY-SA 4.0
2021-08-31T17:38:40.553Z
Indeed there's already a question here: [Why is Somalia so dry?](https://earthscience.stackexchange.com/questions/20956/why-is-somalia-so-dry)
JeopardyTempest
CC BY-SA 4.0
2021-08-31T22:13:06.293Z
@JeopardyTempest should we mark this as duplicate?
f.thorpe
CC BY-SA 4.0
2021-08-31T22:21:00.933Z
@f.thorpe You're the moderator, you tell me :-p  Yeah, maybe... it's supposed to be a little different by focusing on the opposite question, but in the end the key looks to be Somalia's difference from the rest of that latitude around the globe
JeopardyTempest
<meteorology><wind><rainfall><rain>
Why is equatorial Africa wetter in the west than the east?
rwallace
# Why is equatorial Africa wetter in the west than the east?

(Asked by: username_0 on 2021-08-31)

Looking at equatorial Africa in Google Maps, the western part – Guinea, the Congo – is the dark green of tropical rain forest that I would expect of a wet equatorial region, by analogy with the Amazon basin and similar latitudes in east Asia.

By contrast, the eastern part – Kenya, Tanzania – is the light green of savanna and the light brown of semidesert or desert, indicating much drier conditions that at other longitudes, are more associated with the edges of the Hadley cells, 20-30 degrees away from the equator.

That's not at all the pattern I would've expected. By the basic logic of convection cells, plus analogy with other continents, I would've expected moist conditions across the width of equatorial Africa, but failing that, because the prevailing winds in the tropics blow from the east, I would've expected the eastern part of the continent (which gets wind from the Indian Ocean) to be wet and the western part (which gets wind that has blown some distance over land) to be drier.

Why is it that the western part of equatorial Africa is wet and the eastern part is dry?

[![enter image description here](https://i.sstatic.net/ehETS.jpg)](https://i.sstatic.net/ehETS.jpg)

**Tags:** meteorology, wind, rainfall, rain

> **Comments:**
> **username_1**: Part of the answer probably has to do with topography: if you look at any topographic map of Africa (for instance here: https://commons.m.wikimedia.org/wiki/Category:DEM_maps_of_Africa), you'll see that Congo is in the lowlands, while Kenya and Tanzania are mountainous. Elevation has an impact on temperature and thus on vegetation.  
> **username_2**: Indeed there's already a question here: [Why is Somalia so dry?](https://earthscience.stackexchange.com/questions/20956/why-is-somalia-so-dry)  
> **username_3**: @username_2 should we mark this as duplicate?  
> **username_2**: @username_3 You're the moderator, you tell me :-p  Yeah, maybe... it's supposed to be a little different by focusing on the opposite question, but in the end the key looks to be Somalia's difference from the rest of that latitude around the globe  

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