Semnan, Iran climate
BWk Cold desert
Semnan has a strongly seasonal mild-temperate climate (Cold desert, Köppen BWk). The hottest month is July with an average daily high near 101°F, while the coldest is January averaging around 32°F at night. Precipitation totals about 5 inches a year and is strongly seasonal — December alone averages 0.8 inches while July barely receives 0.12 inches.
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figuresHours of sunshine per day
Estimated sunny hours each month — daylight length × clear-sky fraction · 1991–2020 monthly cloud cover (NASA POWER)Semnan climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 49 | 54 | 66 | 76 | 88 | 98 | 101 | 99 | 92 | 78 | 61 | 52 |
| Avg temp (°F) | 41 | 44 | 53 | 63 | 74 | 83 | 87 | 85 | 78 | 67 | 52 | 44 |
| Avg low (°F) | 32 | 34 | 41 | 51 | 60 | 68 | 73 | 72 | 65 | 55 | 43 | 35 |
| Precipitation (in) | 0.6 | 0.7 | 0.6 | 0.7 | 0.4 | 0.3 | 0.1 | 0.1 | 0.1 | 0.2 | 0.5 | 0.8 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°F) | 49 | 54 | 66 | 76 | 88 | 98 |
| Avg temp (°F) | 41 | 44 | 53 | 63 | 74 | 83 |
| Avg low (°F) | 32 | 34 | 41 | 51 | 60 | 68 |
| Precipitation (in) | 0.6 | 0.7 | 0.6 | 0.7 | 0.4 | 0.3 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°F) | 101 | 99 | 92 | 78 | 61 | 52 |
| Avg temp (°F) | 87 | 85 | 78 | 67 | 52 | 44 |
| Avg low (°F) | 73 | 72 | 65 | 55 | 43 | 35 |
| Precipitation (in) | 0.1 | 0.1 | 0.1 | 0.2 | 0.5 | 0.8 |
How often — frequency of weather events
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 3 | 3 | 3 | 4 | 3 | 1 | 0.8 | 0.6 | 0.7 | 1 | 3 | 3 |
| Days with high ≥ 90°F (days) | — | — | — | 0.5 | 7 | 16 | 18 | 18 | 13 | 1 | — | — |
| Days with low ≤ 32°F (days) | 9 | 4 | 1.0 | — | — | — | — | — | — | — | 0.8 | 6 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 3 | 3 | 3 | 4 | 3 | 1 |
| Days with high ≥ 90°F (days) | — | — | — | 0.5 | 7 | 16 |
| Days with low ≤ 32°F (days) | 9 | 4 | 1.0 | — | — | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 0.8 | 0.6 | 0.7 | 1 | 3 | 3 |
| Days with high ≥ 90°F (days) | 18 | 18 | 13 | 1 | — | — |
| Days with low ≤ 32°F (days) | — | — | — | — | 0.8 | 6 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 49 | 52 | 57 | 58 | 50 | 36 | 36 | 31 | 28 | 37 | 48 | 50 |
| Relative humidity (%) | 61 | 56 | 50 | 44 | 37 | 29 | 29 | 29 | 33 | 41 | 53 | 61 |
| Wind speed (mph) | 4.8 | 5.8 | 6.4 | 6.6 | 7.1 | 9.4 | 10.5 | 9.1 | 7.4 | 6.0 | 5.1 | 4.5 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 49 | 52 | 57 | 58 | 50 | 36 |
| Relative humidity (%) | 61 | 56 | 50 | 44 | 37 | 29 |
| Wind speed (mph) | 4.8 | 5.8 | 6.4 | 6.6 | 7.1 | 9.4 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 36 | 31 | 28 | 37 | 48 | 50 |
| Relative humidity (%) | 29 | 29 | 33 | 41 | 53 | 61 |
| Wind speed (mph) | 10.5 | 9.1 | 7.4 | 6.0 | 5.1 | 4.5 |
Methodology & sources
Temperature — modelled for this location from ERA5-Land reanalysis, a ~9 km global grid, because no long-record weather station is close enough to use.
Precipitation — 1991–2020 normals computed from 17 years of daily observations at Semnan, a weather station, about 9 km from the city centre. The underlying daily records come from NOAA's global station network.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.