Afghanistan has an arid continental climate with considerable temperature and precipitation variation between seasons. Temperatures also vary greatly by altitude, with mountainous regions experiencing temperatures well below zero on an annual basis, yet southern arid regions regularly experiencing temperatures over 35ºC. Precipitation varies considerably with topography, with the southwestern arid region typically experiencing less than 150 millimeters (mm) of precipitation each year, and the northeastern mountain range experiencing more than 1,000 mm. Conditions in Afghanistan also have a complex intra-annual interaction with large-scale climate phenomena, specifically the El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole. The latter is associated with drought conditions in Afghanistan.
- Warming occurred of well over 1ºC across most regions of Afghanistan over the 20th century.
- An increased frequency of hot days and hot nights is expected.
- Warming has been strongest in Afghanistan’s central and southwestern regions, and weakest in the northeast in the vicinity of Afghanistan’s largest glaciers
- Precipitation trends in Afghanistan vary by region, with few areas of the country registering statistically significant changes.
- Between 1901 and 2010, there was a significant increase in drought severity in the southern provinces of Kandahar, Helmand and Nimruz during the wheat growing season (November to May), whereas drought intensity during the corn and rice growing seasons (primarily July to September) worsened significantly in the western third of Afghanistan’s territory. These changes in drought severity were most pronounced in the far western areas bordering Iran.
- Changes in precipitation patterns were observed between 1951–2010 across Afghanistan, including slight (<10%) reductions in mean annual rainfall across the west of the country, and less spring rainfall across all regions.