Climate averages 1991–2020
İzmit weather
in September.
A warm, moderately wet month: the 4th warmest and the 3rd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in İzmit: daytime highs average 25.0°C and nights cool to about 16.5°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 61 mm of rain on roughly 8 days, which makes September a moderately wet month (the 3rd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 30 min on an average September day.
The nearest other city in this atlas is Derince (10 km away). In September its highs average 25.1°C, about as warm as İzmit, with 56 mm of rain.
Among the 138 cities listed in Turkey, İzmit ranks joint 95th of 138 for the warmest September highs and 127th of 138 for the driest September (rainfall, lowest first). The mean September high of those 138 cities is 27.1°C; İzmit is 2.1°C cooler than that mean.
From September to October, average highs fall by 4.6°C to 20.4°C, and monthly rainfall rises from 61 mm to 90 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
İzmit climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 8.8°C1.4°C | 1.4°C | 101 | 13.9 | 9.610 h |
| February | 10.2°C1.8°C | 1.8°C | 90 | 13.4 | 10.611 h |
| March | 13.2°C3.9°C | 3.9°C | 97 | 13.9 | 11.912 h |
| April | 17.9°C7.7°C | 7.7°C | 76 | 11.7 | 13.313 h |
| May | 22.3°C12.4°C | 12.4°C | 73 | 10.9 | 14.414 h |
| June | 25.9°C16.8°C | 16.8°C | 75 | 10.6 | 15.015 h |
| July | 28.0°C19.2°C | 19.2°C | 43 | 6.5 | 14.815 h |
| August | 28.2°C19.8°C | 19.8°C | 41 | 6.4 | 13.814 h |
| September, selected | 25.0°C16.5°C | 16.5°C | 61 | 8.4 | 12.513 h |
| October | 20.4°C12.6°C | 12.6°C | 90 | 11.0 | 11.211 h |
| November | 15.5°C7.3°C | 7.3°C | 80 | 10.4 | 10.010 h |
| December | 10.5°C3.4°C | 3.4°C | 110 | 13.5 | 9.39 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
- Derince in SeptemberTurkey · 10 kmHigh 25.1°C · Low 16.7°C · 56 mm rain
- Adapazarı in SeptemberTurkey · 40 kmHigh 24.4°C · Low 14.8°C · 56 mm rain
- Gebze in SeptemberTurkey · 42 kmHigh 23.7°C · Low 16.6°C · 45 mm rain
- Yalova in SeptemberTurkey · 56 kmHigh 25.4°C · Low 17.6°C · 48 mm rain
- Sultanbeyli in SeptemberTurkey · 60 kmHigh 23.7°C · Low 17.5°C · 48 mm rain
- Sancaktepe in SeptemberTurkey · 64 kmHigh 23.7°C · Low 18.0°C · 48 mm rain
- Bilecik in SeptemberTurkey · 69 kmHigh 25.0°C · Low 13.2°C · 24 mm rain
- Ümraniye in SeptemberTurkey · 73 kmHigh 23.5°C · Low 17.9°C · 46 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 İzmit) is explained once on the İzmit year overview and on the Sources, method and limits page.