Climate zones in Saint Helena, 1991 to 2020
Share of Saint Helena's classified land in each Köppen-Geiger zone in 1991 to 2020. Zones under 0.05% are left out. The 229 map cells used cover 47% of the country's outline (about 171 km²).
By major group: C (temperate) 53%, B (arid) 47%, E (polar) 0.4%.
Cfb, temperate oceanic, is the main climate of Saint Helena, covering 52% of its classified land in 1991 to 2020, with BWh (hot desert) next at 34%. In plain terms, temperate oceanic means mild and damp, with no extremes. Under the middle-of-the-road scenario (SSP2-4.5), 7.5% 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 Saint Helena'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) | 12% | 0.4% | BSh +9.9 percentage points | BWh -9.9 percentage points |
| 2071 to 2099, SSP1-2.6 (low emissions) | 7.9% | 0.4% | BSh +3.5 percentage points | BWh -3.5 percentage points |
| 2071 to 2099, SSP2-4.5 (middle of the road) | 7.5% | 0.4% | BSh +3.5 percentage points | BWh -3.5 percentage points |
| 2071 to 2099, SSP5-8.5 (high emissions) | 6.3% | 0.4% | BWh +2.5 percentage points | BSh -2.5 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) |
|---|---|---|---|---|---|
| Cfb Temperate oceanic | 50% | 52% | 50% | 51% | 53% |
| BWh Hot desert | 44% | 34% | 31% | 31% | 37% |
| BSh Hot semi-arid (steppe) | 3% | 13% | 16% | 16% | 10% |
| Cfc Subpolar oceanic | 2% | 0.4% | 2.8% | 2.4% | 0.4% |
| ET Tundra | 0.8% | 0.4% | - | - | - |
Percentages are of the country's classified land in each map. A dash means under 0.05%.
Zones found in Saint Helena
Data: Beck et al. (2023), CC BY 4.0; country outlines from Natural Earth. In 1901 to 1930 the most common zone was Cfb. See data sources and licences.