Būmahen climate — normals and trends
Būmahen (Iran) has a cold semi-arid climate (BSk) under the Köppen-Geiger classification. Its mean annual temperature is 10.1 °C and it receives 329 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (24.8 °C on average) and the coldest is January (-5.0 °C). Rainfall peaks in March.
Būmahen averages 123 frost days, 21 hot days (≥ 30 °C) and 64 rainy days per year.
Būmahen has warmed by +2.6 °C between 1940 and 2025, or +0.31 °C per decade. This trend is statistically significant.
The number of frost days there went from about 139 to 107 per year over the period.
The hottest day of the period reached 35.0 °C (on 8 July 2011) and the coldest -25.0 °C (on 6 January 1942).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
BūmahenTehran
- coords
- 35.73°, 51.87°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
10.1°C
Average daily high
14.3°C
Average daily low
5.6°C
Annual rainfall
329mm
Sunshine / day
10.9h
Mean relative humidity
45%
Average peak wind
11.8km/h
Seasonal range
29.8°C
Frost days (< 0 °C)
123 d/yr
Hot days (≥ 30 °C)
21 d/yr
Rainy days (≥ 1 mm)
64 d/yr
Annual snowfall
103.7 cm
Average feels-like high
11.6 °C
Average feels-like low
2.2 °C
Average peak gust
34.5 km/h
Tropical nights (≥ 20 °C)
35 d/yr
Solar radiation
19.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.6 °C
since 1940
+0.3 °C per decade · r² = 0.41 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
35.0 °C
8 July 2011
Coldest day
-25.0 °C
6 January 1942
Wettest day
42 mm
3 April 1968
Windiest day
25.3 km/h
10 April 2000
Strongest gust
92.5 km/h
21 February 1985
Hottest feels-like
33.2 °C
21 July 2025
Coldest feels-like
-30.9 °C
6 January 1942
Snowiest day
21.1 cm
1 December 1972
Sunniest day
13.4 h
22 June 1947
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 3.9 °C | +4.8 °C | 11 mm | -25 mm |
| Feb | 1.4 °C | +0.8 °C | 39 mm | -4 mm |
| Mar | 10.3 °C | +4.7 °C | 49 mm | -12 mm |
| Apr | 17.4 °C | +4.7 °C | 34 mm | -17 mm |
| May | 24.4 °C | +4.9 °C | 10 mm | -19 mm |
| Jun | 27.0 °C | +0.9 °C | 9 mm | +2 mm |
| Jul | 30.7 °C | +1.6 °C | 5 mm | +0 mm |
| Aug | 30.4 °C | +2.5 °C | 0 mm | -4 mm |
| Sep | 25.0 °C | +1.3 °C | 1 mm | -4 mm |
| Oct | 20.3 °C | +3.8 °C | 0 mm | -19 mm |
| Nov | 13.2 °C | +4.8 °C | 1 mm | -34 mm |
| Dec | 4.7 °C | +2.7 °C | 35 mm | -0 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Būmahen?
Būmahen has a cold semi-arid climate (Köppen BSk). Over 1940-2025, the average annual temperature is 10.1 °C and it receives 329 mm of precipitation per year.
What is the hottest day ever recorded in Būmahen?
The hottest day measured in Būmahen between 1940 and 2025 was 8 July 2011, reaching 35.0 °C.
What is the coldest day in Būmahen?
The coldest day measured in Būmahen between 1940 and 2025 was 6 January 1942, at -25.0 °C.
Does it snow in Būmahen?
Yes. Būmahen gets on average 103.7 cm of snow per year and has around 123 frost days.
Has the climate of Būmahen warmed?
Yes: Būmahen warmed by +2.6 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Būmahen?
The wettest day measured in Būmahen between 1940 and 2025 was 3 April 1968, with 42 mm of rain in 24 hours.
What was the windiest day in Būmahen?
The windiest day measured in Būmahen between 1940 and 2025 was 10 April 2000, with winds reaching 25.3 km/h.
What is the warmest month in Būmahen?
The warmest month in Būmahen is July (24.8 °C on average); the coldest is January (-5.0 °C).
How much does it rain in Būmahen?
Būmahen receives on average 329 mm of precipitation per year, spread over about 64 rainy days.
Is it sunny in Būmahen?
Būmahen gets on average 10.9 hours of sunshine per day, roughly 3,979 hours per year over 1940-2025.
What is the biggest single-day snowfall in Būmahen?
The heaviest 24-hour snowfall measured in Būmahen between 1940 and 2025 was 1 December 1972, with 21.1 cm.
Are there tropical nights in Būmahen?
Yes: Būmahen has on average 35 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Būmahen?
In Būmahen, between 1940 and 2025, the highest apparent temperature reached 33.2 °C on 21 July 2025, and the lowest was -30.9 °C on 6 January 1942.
Compare Būmahen with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Būmahen