Climate averages 1991–2020
Zanjan weather
by month.
See how the year changes. August has the highest average daily maximum; August has the lowest average monthly rainfall.
Pleasant-weather months by our simple rule: JuneJulySeptemberOctober
Long-term climate patterns, not a forecast for a particular trip.
Across the year Zanjan averages a daytime high of 16.6°C and a nighttime low of 4.4°C, with about 468 mm of rain on roughly 93 days. August is the warmest month (average high 29.1°C) and January the coolest (2.2°C). April is the wettest month with 76 mm; August is the driest with 5.8 mm.
Months with pleasant weather by a simple rule (average high between 18°C and 29°C, average low of at least 5°C and at most 8 rain days): June, July, September and October. This looks at temperature and rain only, not humidity, wind, sea temperature or crowds.
The annual picture
A year in Zanjan
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
Zanjan climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 2.2°C-7.2°C | -7.2°C | 43 | 9.0 | 10.010 h |
| February | 4.1°C-6.1°C | -6.1°C | 53 | 10.3 | 10.811 h |
| March | 10.2°C-1.5°C | -1.5°C | 68 | 12.9 | 11.912 h |
| April | 16.5°C3.7°C | 3.7°C | 76 | 13.4 | 13.113 h |
| May | 21.8°C8.5°C | 8.5°C | 58 | 12.4 | 14.114 h |
| June | 26.6°C12.1°C | 12.1°C | 16 | 4.6 | 14.615 h |
| July | 28.5°C13.9°C | 13.9°C | 9.7 | 2.8 | 14.414 h |
| August | 29.1°C14.4°C | 14.4°C | 5.8 | 2.1 | 13.614 h |
| September | 25.6°C11.9°C | 11.9°C | 7.9 | 2.1 | 12.512 h |
| October | 19.1°C7.2°C | 7.2°C | 35 | 6.6 | 11.311 h |
| November | 10.4°C0.5°C | 0.5°C | 55 | 8.6 | 10.310 h |
| December | 4.9°C-4.4°C | -4.4°C | 40 | 7.9 | 9.710 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
Nearby cities
- MīānehIran · 108 kmHigh 20.2°C · Low 7.8°C · 341 mm rain a year
- RashtIran · 118 kmHigh 19.2°C · Low 11.6°C · 1,521 mm rain a year
- Bandar-e AnzalīIran · 123 kmHigh 18.3°C · Low 15.5°C · 1,222 mm rain a year
- TākestānIran · 127 kmHigh 20.3°C · Low 6.9°C · 289 mm rain a year
- QazvinIran · 142 kmHigh 18.9°C · Low 7.8°C · 434 mm rain a year
- LāhījānIran · 147 kmHigh 20.1°C · Low 11.8°C · 1,329 mm rain a year
- AlvandIran · 150 kmHigh 19.8°C · Low 7.3°C · 434 mm rain a year
- MoḩammadīyehIran · 159 kmHigh 19.3°C · Low 7.3°C · 349 mm rain a year
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 limitsWhat do the high and low temperatures mean?
We average the daily maximum and daily minimum for each calendar month over 1991–2020. They are not record extremes, a forecast range or temperatures at a fixed time of day.
How is a rain day counted?
A local calendar day (standard time, UTC+3:30, no daylight saving) with at least 1 mm of total precipitation counts as one rain day. We count these for each year and month, then average across 30 years. The average does not predict which days will be wet.
Where do the numbers come from?
ERA5-Land (temperature) and ERA5 (precipitation) reanalysis from the Copernicus Climate Change Service, read from the Open-Meteo open-data archive. Temperature comes from the 0.1° model cell at 36.70°, 48.50° (3 km from the city centre), adjusted up by 0.7°C for the difference between the city's elevation (1,666 m) and the cell's (1,775 m). Rain comes from the 0.25° cell at 36.75°, 48.50°. These are model estimates, not weather-station readings; coast, hills and city streets can differ.
Does this page show sunshine, humidity or sea temperature?
No. The data used here contain air temperature and precipitation only. Daylight hours are calculated from the city's latitude (sunrise to sunset), not measured sunshine.