Karaj is warmest in July, averaging 27° by day and 14° at night. The wettest month is November with 99 mm, and the year brings about 595 mm in total.
Month by month
| Month | High | Low | Rain | Daylight | Good for |
|---|---|---|---|---|---|
| January | -0° | -10° | 56 mm | 9.8 h | Cool |
| February | 1° | -9° | 64 mm | 10.7 h | Cool |
| March | 6° | -4° | 53 mm | 11.7 h | Cool |
| April | 13° | 1° | 33 mm | 12.9 h | Mild |
| May | 18° | 6° | 43 mm | 13.9 h | Sightseeing |
| June | 25° | 11° | 18 mm | 14.4 h | Sightseeing |
| July | 27° | 14° | 28 mm | 14.2 h | Beach weather |
| August | 26° | 14° | 19 mm | 13.4 h | Beach weather |
| September | 22° | 10° | 45 mm | 12.2 h | Sightseeing |
| October | 15° | 4° | 78 mm | 11.1 h | Mild |
| November | 7° | -4° | 99 mm | 10.1 h | Cool |
| December | 2° | -8° | 59 mm | 9.6 h | Cool |
High and low are average daily maximum and minimum, rain is typical monthly total, daylight is the hours between sunrise and sunset mid-month. Climate normals from NASA POWER — averages, not promises.
When to go
Beach weather: July and August — highs around 27°, nights no colder than 14°, and at most 28 mm of rain in a month.
Walking the city: May, June and September — highs of 18–25° and no more than 45 mm of rain a month.