Climate averages 1991–2020
Karaj weather
in December.
A cold, fairly dry month: the 10th warmest and the joint 8th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a cold month in Karaj: daytime highs average 7.5°C and nights cool to about -3.3°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 37 mm of rain on roughly 7 days, which makes December a fairly dry month (the joint 8th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 9 h 47 min on an average December day.
The nearest other city in this atlas is Moḩammad Shahr (10 km away). In December its highs average 8.0°C, 0.5°C warmer than Karaj, with 37 mm of rain.
Among the 128 cities listed in Iran, Karaj ranks joint 90th of 128 for the warmest December highs and joint 59th of 128 for the driest December (rainfall, lowest first). The mean December high of those 128 cities is 10.9°C; Karaj is 3.4°C cooler than that mean.
From December to January, average highs fall by 2.3°C to 5.2°C, and monthly rainfall stays at 37 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
Karaj climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 5.2°C-6.2°C | -6.2°C | 37 | 7.0 | 10.010 h |
| February | 7.3°C-4.4°C | -4.4°C | 40 | 7.8 | 10.911 h |
| March | 12.9°C0.2°C | 0.2°C | 48 | 9.0 | 11.912 h |
| April | 19.2°C5.9°C | 5.9°C | 42 | 7.7 | 13.113 h |
| May | 25.6°C11.4°C | 11.4°C | 15 | 3.5 | 14.014 h |
| June | 31.9°C17.2°C | 17.2°C | 2.7 | 0.7 | 14.515 h |
| July | 34.9°C20.8°C | 20.8°C | 1.4 | 0.4 | 14.314 h |
| August | 34.0°C20.2°C | 20.2°C | 1.7 | 0.2 | 13.514 h |
| September | 29.1°C15.4°C | 15.4°C | 1.6 | 0.4 | 12.412 h |
| October | 21.8°C9.3°C | 9.3°C | 14 | 2.8 | 11.311 h |
| November | 12.9°C1.8°C | 1.8°C | 35 | 6.0 | 10.310 h |
| December, selected | 7.5°C-3.3°C | -3.3°C | 37 | 6.9 | 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
- Moḩammad Shahr in DecemberIran · 10 kmHigh 8.0°C · Low -2.9°C · 37 mm rain
- Kamālshahr in DecemberIran · 11 kmHigh 7.5°C · Low -2.9°C · 38 mm rain
- Shahre Jadide Andisheh in DecemberIran · 17 kmHigh 8.3°C · Low -2.3°C · 37 mm rain
- Shahrīār in DecemberIran · 20 kmHigh 8.5°C · Low -2.1°C · 37 mm rain
- Bāghestān in DecemberIran · 24 kmHigh 9.2°C · Low -1.4°C · 43 mm rain
- Mehestan in DecemberIran · 28 kmHigh 5.8°C · Low -3.4°C · 34 mm rain
- Naz̧arābād in DecemberIran · 37 kmHigh 7.7°C · Low -1.4°C · 40 mm rain
- Eslamshahr in DecemberIran · 38 kmHigh 9.3°C · Low -1.0°C · 45 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 Karaj) is explained once on the Karaj year overview and on the Sources, method and limits page.
Shahrīār, Moḩammad Shahr and Shahre Jadide Andisheh lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.