Weather in Tehran

Tehran is in Iran at 35.7°N. The 2001–2020 NASA POWER daily record describes a continental climate with a wide temperature swing. Rain is about 311 mm of rain spread through the year. The wettest month is November at 45 mm; the driest is June at 6 mm.

July is the warmest month (average 30.6°C, high 37.7°C) and January is the coolest (average 4.2°C, low -0.9°C). From the coolest night in January (-0.9°C) to the hottest afternoon in July (37.7°C), the raw range is 38.6°C. On this site the months that score closest to a 22°C day, lighter rain, and moderate humidity are May, June, and September.

Temperature through the year

The heat peaks in July, when the typical afternoon is 37.7°C. The opposite pole is January, when mornings average -0.9°C.

Mean high across all twelve months is 23.6°C and mean low is 11.0°C. These are 20-year grid averages, so a city station can read a few degrees warmer or cooler.

When Tehran gets wet

Annual rainfall is 311 mm. November leads at 45 mm; June is lightest at 6 mm.

A rainy day here is a day with at least 1 mm in the NASA POWER series. November averages 9 such days; June averages 2.

The calendar in Tehran

The year bottoms out in January. Plan for -0.9°C at night and 9.3°C in the afternoon. February: 11.9°C high, 0.4°C low, 35 mm rain, 55% humidity. In March, Tehran averages 17.6°C by day and 4.7°C at night, with 35 mm of rain. April brings 39 mm and 7 rainy days; temperatures run from 9.3°C to 22.6°C. May stands apart from the months beside it: 29.2°C / 14.9°C and 15 mm. June is the driest month, averaging only 6 mm across 2 rainy days. Highs sit near 35.3°C.

July is the warmest month. Afternoon highs average 37.7°C and nights settle near 23.5°C, with 7 mm of rain. August brings 8 mm and 2 rainy days; temperatures run from 22.6°C to 36.4°C. September stands apart from the months beside it: 32.0°C / 18.6°C and 16 mm. October stands apart from the months beside it: 24.9°C / 12.9°C and 36 mm. November is the wettest month — 45 mm and 9 rainy days, with 54% humidity. In December, Tehran averages 10.7°C by day and 0.7°C at night, with 35 mm of rain.

Best months to visit Tehran

The three months with the highest comfort score are May, June, and September: May (22.1°C average, 15 mm, 38% humidity); June (27.8°C average, 6 mm, 25% humidity); September (25.3°C average, 16 mm, 28% humidity). They fall in calendar order. The score rewards averages near 22°C, lower rainfall, and humidity near 60%. It is a climate score, not a festival or price calendar.

If you prefer the hottest stretch, that is July. The coolest stretch is January.

How Tehran compares inside Iran

Karaj is about 42 km away: Tehran is 10.0°C warmer than Karaj in its hottest month and 198 mm drier over the year than Karaj. Karaj’s wettest month is November (80 mm) versus November here.

Isfahan is about 339 km away: Tehran is 1.8°C warmer than Isfahan in its hottest month and 146 mm wetter over the year than Isfahan. Isfahan’s wettest month is March (28 mm) versus November here.

Tabriz is about 528 km away: Tehran is 7.4°C warmer than Tabriz in its hottest month and 75 mm wetter over the year than Tabriz. Tabriz’s wettest month is April (44 mm) versus November here.