What a BSh climate is like
BSh Hot semi-arid (steppe). A band of dry grassland and scrub, usually found on the edges of hot deserts. It gets more rain than a desert, but still not enough for most trees.
The rules behind the code, in plain English:
- Arid, but not dry enough to be a desert: yearly rainfall is between five and ten times the threshold.
- Hot: mean annual temperature of 18 °C or more.
Dataset wording: "Arid, steppe, hot". In the maps of Beck et al. (2023) the class is written: B: MAP < 10 x Pthreshold; S: MAP >= 5 x Pthreshold; h: MAT >= 18.
Hot semi-arid climate (steppe) is dry and hot but gets enough rain to grow grass, so it sits between desert and wetter country. Rain is patchy and often falls in a short season, and droughts are a regular risk. Open grassland and scrub support grazing, and farmers grow drought-tolerant crops such as millet and sorghum. Light clothing, shade and careful water use are part of daily life.
How much of the world is BSh?
- 6.4%of the world's land outside Antarctica, 1991 to 2020
- 8,613,734 km²area, 1991 to 2020
- 2,229cities of 15,000 or more people (GeoNames) have this climate now
In 1901 to 1930 it covered 5.7% of that land, so its area then was 10.23% smaller than in 1991 to 2020.
How the BSh area is projected to change by 2071 to 2099
These figures compare the area of BSh in each future map with 1991 to 2020. They come from the Beck et al. (2023) model projections under three emissions scenarios. They show what the scenarios imply, not what will happen.
| Map | Share of land | Change in area vs 1991 to 2020 |
|---|---|---|
| 1901 to 1930 (past) | 5.7% | -10.23% |
| 1991 to 2020 (now) | 6.4% | - |
| 2071 to 2099, SSP1-2.6 (low emissions) | 7% | +9.99% |
| 2071 to 2099, SSP2-4.5 (middle of the road) | 7.4% | +16.27% |
| 2071 to 2099, SSP5-8.5 (high emissions) | 8.1% | +26.68% |
Shares are of land outside Antarctica. A negative change means the zone shrinks.
What happens to today's BSh land
Of the land that is BSh in 1991 to 2020, this is how much stays BSh and where the rest ends up in 2071 to 2099, by scenario:
| Scenario (2071 to 2099) | Stays BSh | Where the rest goes (biggest first) |
|---|---|---|
| SSP1-2.6, low emissions | 90% | BWh (6.3%), Aw (2%), Cwa (1.1%) |
| SSP2-4.5, middle of the road | 86% | BWh (10%), Aw (2.8%), Cwa (0.9%) |
| SSP5-8.5, high emissions | 76% | BWh (18%), Aw (5.5%) |
Looking back, 78% of today's BSh land was also BSh in 1901 to 1930. The rest was BSk (5.9%), Aw (5%), BWh (5%), Cwa (2%), Cfa (1.9%).
Where BSh is found
The countries with the most BSh land in 1991 to 2020:
| Country | Area | Share of all BSh | Share of the country |
|---|---|---|---|
| Australia | 2,037,571 km² | 24% | 27% |
| India | 625,791 km² | 7.3% | 20% |
| Botswana | 424,364 km² | 4.9% | 73% |
| Brazil | 423,706 km² | 4.9% | 5% |
| Mexico | 394,146 km² | 4.6% | 20% |
| Sudan | 359,823 km² | 4.2% | 19% |
| Namibia | 312,062 km² | 3.6% | 38% |
| Argentina | 269,028 km² | 3.1% | 9.7% |
Places with a BSh climate today
The biggest cities in the 1991 to 2020 map that sit in BSh (at most two per country):
Other arid climates (group B)
Frequently asked questions
What does BSh mean in the Köppen climate classification?
Arid, but not dry enough to be a desert: yearly rainfall is between five and ten times the threshold. Hot: mean annual temperature of 18 °C or more. The code is a short way of writing that: the first letter is the major group (B, arid) and the letters after it say more about rain and temperature.
What is a hot semi-arid (steppe) climate like?
Dry and hot, but with enough rain for grass. A band of dry grassland and scrub, usually found on the edges of hot deserts. It gets more rain than a desert, but still not enough for most trees.
How much of the world has a BSh climate?
6.4% of the world's land outside Antarctica was BSh in 1991 to 2020, about 8,613,734 km² (Beck et al. 2023, 1 km maps).
Will the BSh climate zone grow or shrink?
Under the middle-of-the-road scenario (SSP2-4.5), the area of BSh in 2071 to 2099 is 16.27% larger than in 1991 to 2020. This is a model projection, not a forecast, and it differs under other scenarios (see the table on this page).
Data: Beck et al. (2023), CC BY 4.0. See data sources and licences. Köppen-Geiger classes describe long-term averages, not weather.