Climate averages 1991–2020
Karaj weather
in September.
A hot, very dry month: the 4th warmest and the 2nd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a hot month in Karaj: daytime highs average 29.1°C and nights cool to about 15.4°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 1.6 mm of rain on fewer than one day, which makes September a very dry month (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 26 min on an average September day.
The nearest other city in this atlas is Moḩammad Shahr (10 km away). In September its highs average 29.6°C, about as warm as Karaj, with 1.6 mm of rain.
Among the 128 cities listed in Iran, Karaj ranks joint 80th of 128 for the warmest September highs and joint 74th of 128 for the driest September (rainfall, lowest first). The mean September high of those 128 cities is 31.0°C; Karaj is 2.0°C cooler than that mean.
From September to October, average highs fall by 7.3°C to 21.8°C, and monthly rainfall rises from 1.6 mm to 14 mm.
The annual picture
September 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, selected | 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 | 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
September in nearby cities
- Moḩammad Shahr in SeptemberIran · 10 kmHigh 29.6°C · Low 15.1°C · 1.6 mm rain
- Kamālshahr in SeptemberIran · 11 kmHigh 29.2°C · Low 17.0°C · 1.7 mm rain
- Shahre Jadide Andisheh in SeptemberIran · 17 kmHigh 30.0°C · Low 15.9°C · 1.6 mm rain
- Shahrīār in SeptemberIran · 20 kmHigh 30.3°C · Low 16.3°C · 1.6 mm rain
- Bāghestān in SeptemberIran · 24 kmHigh 31.2°C · Low 16.6°C · 2.5 mm rain
- Mehestan in SeptemberIran · 28 kmHigh 27.2°C · Low 16.0°C · 2.0 mm rain
- Naz̧arābād in SeptemberIran · 37 kmHigh 29.1°C · Low 16.9°C · 2.5 mm rain
- Eslamshahr in SeptemberIran · 38 kmHigh 31.5°C · Low 17.3°C · 1.4 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.