Climate averages 1991–2020
Semnan weather
in December.
A cool, very dry month: the 11th warmest and the 7th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a cool month in Semnan: daytime highs average 8.4°C and nights cool to about 1.2°C. By daytime temperature it is the 11th warmest of the 12 months.
Expect about 10 mm of rain on roughly 3 days, which makes December a very dry month (the 7th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 9 h 48 min on an average December day.
The nearest other city in this atlas is Qā’em Shahr (110 km away). In December its highs average 13.6°C, 5.2°C warmer than Semnan, with 65 mm of rain.
Among the 128 cities listed in Iran, Semnan ranks 81st of 128 for the warmest December highs and joint 2nd of 128 for the driest December (rainfall, lowest first). The mean December high of those 128 cities is 10.9°C; Semnan is 2.5°C cooler than that mean.
From December to January, average highs fall by 1.3°C to 7.1°C, and monthly rainfall rises from 10 mm to 12 mm.
The annual picture
December in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Semnan climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 7.1°C-1.0°C | -1.0°C | 12 | 3.3 | 10.010 h |
| February | 9.6°C0.4°C | 0.4°C | 14 | 3.1 | 10.911 h |
| March | 15.3°C4.7°C | 4.7°C | 18 | 3.9 | 11.912 h |
| April | 21.9°C10.4°C | 10.4°C | 13 | 2.8 | 13.113 h |
| May | 27.7°C15.2°C | 15.2°C | 4.8 | 1.3 | 14.014 h |
| June | 32.8°C19.5°C | 19.5°C | 1.2 | 0.3 | 14.515 h |
| July | 35.3°C22.4°C | 22.4°C | 1.0 | 0.3 | 14.314 h |
| August | 34.3°C21.7°C | 21.7°C | 1.2 | 0.3 | 13.514 h |
| September | 29.8°C18.0°C | 18.0°C | 1.7 | 0.5 | 12.412 h |
| October | 22.8°C12.5°C | 12.5°C | 4.5 | 1.2 | 11.311 h |
| November | 13.9°C5.8°C | 5.8°C | 11 | 3.1 | 10.310 h |
| December, selected | 8.4°C1.2°C | 1.2°C | 10 | 3.2 | 9.810 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Qā’em Shahr in DecemberIran · 110 kmHigh 13.6°C · Low 3.5°C · 65 mm rain
- Sari in DecemberIran · 114 kmHigh 13.8°C · Low 3.7°C · 68 mm rain
- Behshahr in DecemberIran · 125 kmHigh 14.5°C · Low 5.8°C · 59 mm rain
- Bābol in DecemberIran · 126 kmHigh 13.5°C · Low 4.8°C · 65 mm rain
- Āmol in DecemberIran · 136 kmHigh 12.2°C · Low 3.8°C · 133 mm rain
- Būmahen in DecemberIran · 139 kmHigh 4.3°C · Low -3.1°C · 36 mm rain
- Pardīs in DecemberIran · 144 kmHigh 3.2°C · Low -4.7°C · 36 mm rain
- Pākdasht in DecemberIran · 155 kmHigh 9.9°C · Low 0.6°C · 30 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Semnan) is explained once on the Semnan year overview and on the Sources, method and limits page.