Tehran, Iran's sprawling capital at the foot of the Alborz Mountains, pairs Qajar-era palaces and a vast historic bazaar with modern towers, mountain gondolas, and a genuine after-dark cafe culture built around teahouses rather than bars.
Tehran has a cold semi-arid climate strongly shaped by its position at the foot of the Alborz mountain range, at an elevation of roughly 1,200 meters. Summers (June-August) are long, hot, and dry, with daytime highs regularly reaching the low-to-mid 30s°C and minimal rainfall. Winters (December-February) are cold, with January highs averaging around 5°C (41°F) and overnight lows occasionally dropping below freezing; snow is possible, particularly in the northern, higher-elevation districts of the city. Rainfall is generally low year-round, with March the wettest month and August the driest. Tehran's basin location, combined with heavy vehicle traffic, causes recurring air pollution problems, most severe in winter temperature inversions.
Best time to visit
Best: March
Peak Season: April-May and September-October, when mild temperatures coincide with the most comfortable sightseeing conditions
Shoulder Season: March and early November, with cooler evenings but generally pleasant daytime conditions
Avoid: July and August (extreme heat, often exceeding 35°C/95°F with low humidity but intense sun) and the depths of winter, December-February (cold, occasional snow, and heavy pollution from temperature inversions)
Best Reason: Spring and fall bring daytime highs in the high teens to mid-20s°C with low rainfall, making walking tours of Tehran's museums, bazaars, and northern hillside districts far more comfortable than the summer heat or winter smog.
Avoid Reason: Summer heat in Tehran is intense and dry, while winter brings cold temperatures, occasional snow at higher elevations in the north of the city, and Tehran's worst air quality of the year due to temperature inversions trapping traffic pollution over the basin the city sits in.
Summary: March to May (spring) and September to November (fall)
Month-by-month weather
Typical conditions throughout the year.
January
-3 to 5°C / 27 to 41°F
Cold, with occasional snow and Tehran's poorest air quality of the year due to winter temperature inversions
February
-1 to 7°C / 30 to 45°F
Still cold, gradually warming; the Islamic Revolution anniversary on February 11 brings road closures in central Tehran
March
3 to 12°C / 37 to 54°F
Mild and improving; Nowruz around March 20-21 brings major closures and heavy domestic travel demand
April
9 to 19°C / 48 to 66°F
Pleasant spring weather with low rainfall, one of the most comfortable months for sightseeing
May
14 to 26°C / 57 to 79°F
Warm and mostly dry, excellent conditions before the summer heat sets in
June
19 to 32°C / 66 to 90°F
Hot and dry summer conditions begin; still manageable with early starts
July
23 to 35°C / 73 to 95°F
Peak summer heat, dry and intense sun; outdoor sightseeing best limited to early morning and evening
August
22 to 34°C / 72 to 93°F
Hottest, driest month of the year with almost no rainfall
September
17 to 30°C / 63 to 86°F
Heat begins to ease, air quality improves; a strong month for sightseeing
October
10 to 22°C / 50 to 72°F
Mild and comfortable, one of the best months for walking the city and its bazaars
November
4 to 13°C / 39 to 55°F
Cooling quickly; air quality can begin to decline as the winter heating season starts
December
0 to 7°C / 32 to 45°F
Cold, occasional early snow at higher elevations in the north of the city
The seasons
What to expect in each part of the year.
Spring
Months: Mar-May
Widely considered the best season to visit. Mild, pleasant daytime temperatures, blooming parks and gardens in the northern districts, and the major cultural backdrop of Nowruz celebrations (though the holiday itself brings closures).
Summer
Months: Jun-Aug
Hot and dry, with daytime temperatures often exceeding 35°C. Manageable for sightseeing with early starts and shaded breaks during the hottest midday hours, but not the most comfortable season for extended walking.
Fall
Months: Sep-Nov
A second peak season with comfortable daytime temperatures and clearer air than summer, though air quality can begin to decline again by late November as heating season starts.
Winter
Months: Dec-Feb
Cold with occasional snow, especially in the elevated northern neighborhoods, and Tehran's worst air quality of the year due to temperature inversions over the basin.
Crowds & peak times
When to expect tourists and when to avoid them.
- High Season
- March around Nowruz and April-May, October — international and heavy domestic travel demand coincide with the most comfortable weather
- Shoulder Season
- September and early November — fewer crowds with still-favorable weather
- Low Season
- July-August and December-February — extreme summer heat or winter cold and pollution keep visitor numbers lower, aside from the brief spike during the Nowruz holiday itself in Iranian domestic travel
Major events & festivals
Time your visit around what matters.
Nowruz (Persian New Year)
Iran's most important holiday, marking the Persian New Year. Most businesses, government offices, and many shops close for roughly two weeks around the holiday, and domestic travel and hotel prices surge as Iranian families travel. Tehran itself becomes noticeably quieter as residents leave the city, though some cultural sites remain open.
Ramadan
During the Islamic holy month of fasting, many restaurants are closed or curtained off during daylight hours, and eating, drinking, or smoking in public during daylight is against the law and social norm for everyone, including non-fasting visitors. Evenings come alive after the iftar meal breaks the fast, with markets and some restaurants staying open later than usual.
Islamic Revolution Anniversary
National holiday commemorating the 1979 Islamic Revolution, marked by official rallies and marches in Tehran, notably along Azadi Street toward Azadi Square. Expect road closures and heavy security presence in central Tehran on this date.
Sizdah Bedar
A national outdoor picnic day marking the close of the Nowruz holidays, when Tehran families head to parks and green spaces across the city and surrounding countryside. Roads out of the city are heavily congested.