Karaj climate
Karaj is warmest in July, with average highs of 35 °C, and coldest in January, when nights average -6.0 °C. March is the wettest month (50 mm) and July the driest (1.2 mm). Figures are 1991–2020 climate normals.
Across a full year Karaj averages 288 mm of rain, 147 days above 25 °C and 105 days below freezing.
Iran · population 1,448,075 · 1991–2020 normals
Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month
- Warmest month July 35 °C
- Coldest month January -6.0 °C
- Driest month July 1 mm
- Wettest month March 50 mm
- Least cloud September 7 % cloud
- Hottest on record July 40 °C
- Coldest on record January -23 °C
What to expectKaraj through the year
Karaj has a clear annual cycle: average daily highs run from 5.3 °C in January to 35 °C in July, a swing of 29 °C in mean temperature across the year.
Counted across a normal year, 147 days a year reach 25 °C, 99 of them reach 30 °C, 105 nights drop below freezing. The warmest reading in the 1991–2020 record is 40 °C, in July.
Rain is strongly seasonal. March averages 50 mm against 1 mm in July — 43 times as much. Planning around the dry months matters more here than planning around temperature.
Month by month
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| January | 5.3 °C | 38 mm | 39 % |
| February | 7.5 °C | 41 mm | 40 % |
| March | 13.0 °C | 50 mm | 43 % |
| April | 19.3 °C | 46 mm | 44 % |
| May | 25.7 °C | 16 mm | 34 % |
| June | 31.9 °C | 2 mm | 14 % |
| July | 34.9 °C | 1 mm | 11 % |
| August | 34.0 °C | 2 mm | 7 % |
| September | 29.2 °C | 2 mm | 7 % |
| October | 21.9 °C | 16 mm | 24 % |
| November | 13.0 °C | 38 mm | 38 % |
| December | 7.6 °C | 39 mm | 41 % |
Temperature month by month
| Month | Avg high | Avg low | Mean | Record high | Record low | Days above 25 °C | Days above 30 °C | Days below 0 °C |
|---|---|---|---|---|---|---|---|---|
| January | 5.3 °C | -6.0 °C | -0.9 °C | 14.3 °C | -23.3 °C | 0 | 0 | 29 |
| February | 7.5 °C | -4.3 °C | 1.4 °C | 19.7 °C | -20.5 °C | 0 | 0 | 24 |
| March | 13.0 °C | 0.3 °C | 6.8 °C | 29.5 °C | -19.6 °C | 0 | 0 | 15 |
| April | 19.3 °C | 5.8 °C | 13.0 °C | 30.6 °C | -5.3 °C | 3 | 0 | 2 |
| May | 25.7 °C | 11.4 °C | 19.4 °C | 34.6 °C | -1.0 °C | 18 | 4 | 0 |
| June | 31.9 °C | 17.1 °C | 25.4 °C | 39.4 °C | 8.5 °C | 29 | 23 | 0 |
| July | 34.9 °C | 20.7 °C | 28.6 °C | 40.4 °C | 13.0 °C | 31 | 30 | 0 |
| August | 34.0 °C | 20.0 °C | 27.6 °C | 39.7 °C | 9.9 °C | 31 | 30 | 0 |
| September | 29.2 °C | 15.4 °C | 22.7 °C | 35.4 °C | 8.5 °C | 27 | 13 | 0 |
| October | 21.9 °C | 9.3 °C | 15.9 °C | 30.0 °C | 1.5 °C | 7 | 0 | 0 |
| November | 13.0 °C | 1.8 °C | 7.3 °C | 23.2 °C | -12.7 °C | 0 | 0 | 9 |
| December | 7.6 °C | -3.1 °C | 1.7 °C | 19.0 °C | -20.2 °C | 0 | 0 | 25 |
Rain, sun and wind month by month
| Month | Rainfall | Wet days | Daylight | Cloud cover | Humidity | Wind |
|---|---|---|---|---|---|---|
| January | 38 mm | 7 | 10 h/day | 39 % | 61 % | 9.6 km/h |
| February | 41 mm | 8 | 11 h/day | 40 % | 61 % | 11 km/h |
| March | 50 mm | 9 | 12 h/day | 43 % | 57 % | 13 km/h |
| April | 46 mm | 8 | 13 h/day | 44 % | 50 % | 14 km/h |
| May | 16 mm | 3 | 14 h/day | 34 % | 37 % | 15 km/h |
| June | 2 mm | 0 | 15 h/day | 14 % | 27 % | 15 km/h |
| July | 1 mm | 0 | 14 h/day | 11 % | 27 % | 15 km/h |
| August | 2 mm | 0 | 14 h/day | 7 % | 26 % | 14 km/h |
| September | 2 mm | 0 | 12 h/day | 7 % | 28 % | 13 km/h |
| October | 16 mm | 3 | 11 h/day | 24 % | 40 % | 11 km/h |
| November | 38 mm | 6 | 10 h/day | 38 % | 57 % | 9.9 km/h |
| December | 39 mm | 7 | 9.7 h/day | 41 % | 60 % | 9.0 km/h |
How Karaj compares
The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.
| Destination | Summer high | Winter low | Rain per year | Days above 25 °C |
|---|---|---|---|---|
| Karaj | 35 °C | -6.0 °C | 288 mm | 147 |
| Fardīs · Iran | 35 °C | -5.6 °C | 290 mm | 151 |
| Shahrīār · Iran | 36 °C | -4.8 °C | 291 mm | 157 |
| Naz̧arābād · Iran | 35 °C | -4.1 °C | 356 mm | 145 |
| Eslamshahr · Iran | 37 °C | -3.5 °C | 313 mm | 168 |
| Golestān · Iran | 37 °C | -3.2 °C | 302 mm | 171 |
| Tehran · Iran | 36 °C | -5.0 °C | 346 mm | 156 |
Planning a trip? See the best time to visit Karaj.
QuestionsCommon questions about Karaj’s climate
When is the best time to visit Karaj?
That depends on what you want, so the honest answer is a comparison rather than a single month. May, September, October sit closest to 20 °C on average, July is the warmest month and July the driest. The month-by-month table above has the full picture.
How hot does Karaj get?
In July, the warmest month, daily highs average 35 °C. About 99 days a year pass 30 °C. The highest value in the 1991–2020 record is 40 °C.
How cold does it get in winter?
Nights average -6.0 °C in January, the coldest month. A normal year has 105 nights below freezing.
Which month is wettest in Karaj?
March, averaging 50 mm over 9 days with rain. The driest month is July with 1 mm. The year as a whole averages 288 mm.
Are these figures a forecast?
No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Karaj rather than what any particular week will bring. Individual years can differ substantially from the normal.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.