Tehran Province exhibits a diverse climate depending on elevation, broadly classified as semi-arid (Köppen: BSk) in the city and southern plains, transitioning to a Mediterranean and Continental climate in the northern mountains.
In the central and southern urban areas, summers are long, hot, and dry, with average high temperatures in July frequently exceeding 36°C (97°F). Winters are relatively short and cool, with average January lows around 1°C (34°F). Precipitation is generally low, averaging 200-250mm annually, with the vast majority falling between November and April. Snowfall in the city is occasional but usually brief, whereas the northern mountains receive heavy snow, supporting a robust winter sports industry.
A significant meteorological and environmental feature of the province is severe winter air pollution. Cold air descending from the mountains can create a temperature inversion, trapping vehicle exhaust and industrial smog over the metropolitan basin for days at a time. The best times to visit are generally spring (April to May) and autumn (September to October) when temperatures are mild and the air is clearer.
