Climate zones in Yemen, 1991 to 2020
Share of Yemen's classified land in each Köppen-Geiger zone in 1991 to 2020. Zones under 0.05% are left out. The 549,451 map cells used cover 100% of the country's outline (about 453,567 km²).
By major group: B (arid) 100%, C (temperate) 0.1%.
Almost all of Yemen is one climate: BWh, hot desert, which covers 96% of its classified land in 1991 to 2020. In plain terms, hot desert means very dry and hot. Under the middle-of-the-road scenario (SSP2-4.5), 5.2% of its land is projected to be in a different zone by 2071 to 2099, with the biggest gain going to BSh (hot semi-arid (steppe)).
How Yemen's zones have changed and may change
Each row compares a map with 1991 to 2020. "Share in a different zone" is the share of the country's area whose class is different from 1991 to 2020. Future rows are model projections under an emissions scenario, not forecasts.
| Map | Share in a different zone | Different major group | Biggest gain | Biggest loss |
|---|---|---|---|---|
| 1901 to 1930 (past) | 1% | 0.1% | BWh +0.5 percentage points | BWk -0.7 percentage points |
| 2071 to 2099, SSP1-2.6 (low emissions) | 4.8% | 0.2% | BSh +3.8 percentage points | BWh -2.4 percentage points |
| 2071 to 2099, SSP2-4.5 (middle of the road) | 5.2% | 0.2% | BSh +4.3 percentage points | BWh -2.4 percentage points |
| 2071 to 2099, SSP5-8.5 (high emissions) | 6% | 0.3% | BSh +5 percentage points | BWh -3 percentage points |
For the past row, the comparison runs the other way: the 1901 to 1930 map against 1991 to 2020.
Zone shares by map
| Zone | 1901 to 1930 | 1991 to 2020 | SSP1-2.6 (2071 to 2099) | SSP2-4.5 (2071 to 2099) | SSP5-8.5 (2071 to 2099) |
|---|---|---|---|---|---|
| BWh Hot desert | 96% | 96% | 94% | 94% | 93% |
| BSh Hot semi-arid (steppe) | 1.4% | 1.4% | 5.2% | 5.7% | 6.5% |
| BWk Cold desert | 2% | 1.3% | 0.1% | - | - |
| BSk Cold semi-arid (steppe) | 0.8% | 0.9% | 0.7% | 0.2% | - |
| Cwb Subtropical highland (dry winter) | 0.1% | 0.1% | 0.2% | 0.1% | - |
| Cwa Humid subtropical with dry winter | - | - | - | 0.1% | 0.2% |
| Aw Tropical savannah | - | - | - | - | 0.1% |
Percentages are of the country's classified land in each map. A dash means under 0.05%.
Cities in Yemen and their climate zones
| City | 1991 to 2020 | 2071 to 2099, SSP2-4.5 |
|---|---|---|
| Sanaa | BWh Hot desert | BWh Hot desert |
| Aden | BWh Hot desert | BWh Hot desert |
| Taiz | BSh Hot semi-arid (steppe) | BSh Hot semi-arid (steppe) |
| Ibb | BSh Hot semi-arid (steppe) | BSh Hot semi-arid (steppe) |
| Al Ḩudaydah | BWh Hot desert | BWh Hot desert |
| Mukalla | BWh Hot desert | BWh Hot desert |
Zones found in Yemen
Data: Beck et al. (2023), CC BY 4.0; country outlines from Natural Earth. In 1901 to 1930 the most common zone was BWh. See data sources and licences.