What a Dsa climate is like
Dsa Hot-summer continental with dry summer. A rare climate of mountain basins and interiors, with a dry summer and a freezing winter.
The rules behind the code, in plain English:
- Cold (coldest month at or below 0 °C).
- Dry summer: the driest summer month gets under 40 mm and under a third of the wettest winter month.
- Hot summer: the warmest month averages 22 °C or more.
Dataset wording: "Cold, dry summer, hot summer". In the maps of Beck et al. (2023) the class is written: D: Not B and Thot > 10 and Tcold <= 0; s: Psdry < 40 and Psdry < Pwwet/3; a: Thot >= 22.
Hot-summer continental climate with a dry summer has cold winters and hot, dry summers. It is a rare mix, found in some high, inland places near Mediterranean-type regions. Snow lies in winter, then the land turns dry and sunny and needs irrigation for farming. Orchards, grains and grazing are typical, and homes are built for both winter cold and summer heat.
How much of the world is Dsa?
- 0.3%of the world's land outside Antarctica, 1991 to 2020
- 380,922 km²area, 1991 to 2020
- 125cities of 15,000 or more people (GeoNames) have this climate now
In 1901 to 1930 it covered 0.3% of that land, so its area then was 2.74% smaller than in 1991 to 2020.
How the Dsa area is projected to change by 2071 to 2099
These figures compare the area of Dsa 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) | 0.3% | -2.74% |
| 1991 to 2020 (now) | 0.3% | - |
| 2071 to 2099, SSP1-2.6 (low emissions) | 0.3% | +12.96% |
| 2071 to 2099, SSP2-4.5 (middle of the road) | 0.3% | +15.74% |
| 2071 to 2099, SSP5-8.5 (high emissions) | 0.4% | +30.03% |
Shares are of land outside Antarctica. A negative change means the zone shrinks.
What happens to today's Dsa land
Of the land that is Dsa in 1991 to 2020, this is how much stays Dsa and where the rest ends up in 2071 to 2099, by scenario:
| Scenario (2071 to 2099) | Stays Dsa | Where the rest goes (biggest first) |
|---|---|---|
| SSP1-2.6, low emissions | 61% | Csa (29%), BSk (8.5%), Dfa (2%) |
| SSP2-4.5, middle of the road | 40% | Csa (41%), BSk (18%), Dfa (0.6%) |
| SSP5-8.5, high emissions | 12% | Csa (56%), BSk (29%), BSh (2.5%) |
Looking back, 61% of today's Dsa land was also Dsa in 1901 to 1930. The rest was Dsb (28%), BSk (7.3%), Dfa (1.9%), Dfb (1.2%).
Where Dsa is found
The countries with the most Dsa land in 1991 to 2020:
| Country | Area | Share of all Dsa | Share of the country |
|---|---|---|---|
| Iran | 130,259 km² | 34% | 8% |
| Turkey | 90,268 km² | 24% | 12% |
| Afghanistan | 56,696 km² | 15% | 8.8% |
| Kazakhstan | 44,055 km² | 12% | 1.6% |
| United States | 30,153 km² | 7.9% | 0.3% |
| Kyrgyzstan | 10,192 km² | 2.7% | 5.1% |
| Uzbekistan | 7,585 km² | 2% | 1.7% |
| Tajikistan | 3,953 km² | 1% | 2.8% |
Places with a Dsa climate today
The biggest cities in the 1991 to 2020 map that sit in Dsa (at most two per country):
Other cold (continental) climates (group D)
- Dsb Warm-summer continental with dry summer
- Dsc Subarctic with dry summer
- Dsd Subarctic with dry summer and very cold winter
- Dwa Hot-summer continental with dry winter
- Dwb Warm-summer continental with dry winter
- Dwc Subarctic with dry winter
- Dwd Subarctic with dry winter and very cold winter
- Dfa Hot-summer humid continental
- Dfb Warm-summer humid continental
- Dfc Subarctic (boreal)
- Dfd Subarctic with very cold winter
- All 30 zones
Frequently asked questions
What does Dsa mean in the Köppen climate classification?
Cold (coldest month at or below 0 °C). Dry summer: the driest summer month gets under 40 mm and under a third of the wettest winter month. Hot summer: the warmest month averages 22 °C or more. The code is a short way of writing that: the first letter is the major group (D, cold (continental)) and the letters after it say more about rain and temperature.
What is a hot-summer continental with dry summer climate like?
Cold winters and hot, dry summers. A rare climate of mountain basins and interiors, with a dry summer and a freezing winter.
How much of the world has a Dsa climate?
0.3% of the world's land outside Antarctica was Dsa in 1991 to 2020, about 380,922 km² (Beck et al. 2023, 1 km maps).
Will the Dsa climate zone grow or shrink?
Under the middle-of-the-road scenario (SSP2-4.5), the area of Dsa in 2071 to 2099 is 15.74% 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.