Climate averages 1991–2020
Dortmund weather
in September.
A mild, moderately wet month: the 4th warmest and the joint 6th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Dortmund: daytime highs average 18.6°C and nights cool to about 11.3°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 75 mm of rain on roughly 12 days, which makes September a moderately wet month (the joint 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 42 min on an average September day.
The nearest other city in this atlas is Witten (11 km away). In September its highs average 18.5°C, about as warm as Dortmund, with 74 mm of rain.
Among the 120 cities listed in Germany, Dortmund ranks joint 76th of 120 for the warmest September highs and joint 104th of 120 for the driest September (rainfall, lowest first). The mean September high of those 120 cities is 18.8°C; Dortmund is 0.2°C cooler than that mean.
From September to October, average highs fall by 4.8°C to 13.8°C, and monthly rainfall falls from 75 mm to 74 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
Dortmund climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 4.7°C0.1°C | 0.1°C | 83 | 14.3 | 8.48 h |
| February | 5.9°C0.2°C | 0.2°C | 68 | 12.5 | 9.910 h |
| March | 9.5°C2.2°C | 2.2°C | 72 | 13.7 | 11.812 h |
| April | 13.9°C5.1°C | 5.1°C | 57 | 11.5 | 13.814 h |
| May | 17.7°C9.0°C | 9.0°C | 69 | 12.7 | 15.616 h |
| June | 20.5°C12.2°C | 12.2°C | 76 | 12.6 | 16.517 h |
| July | 22.6°C14.4°C | 14.4°C | 90 | 14.2 | 16.116 h |
| August | 22.4°C14.3°C | 14.3°C | 87 | 13.5 | 14.615 h |
| September, selected | 18.6°C11.3°C | 11.3°C | 75 | 12.0 | 12.713 h |
| October | 13.8°C8.0°C | 8.0°C | 74 | 12.3 | 10.711 h |
| November | 8.8°C4.1°C | 4.1°C | 75 | 14.1 | 8.99 h |
| December | 5.3°C1.2°C | 1.2°C | 87 | 14.7 | 7.98 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
- Witten in SeptemberGermany · 11 kmHigh 18.5°C · Low 11.5°C · 74 mm rain
- Castrop-Rauxel in SeptemberGermany · 12 kmHigh 18.7°C · Low 11.4°C · 74 mm rain
- Lünen in SeptemberGermany · 12 kmHigh 18.9°C · Low 11.5°C · 75 mm rain
- Hagen in SeptemberGermany · 17 kmHigh 18.4°C · Low 11.6°C · 92 mm rain
- Bochum in SeptemberGermany · 18 kmHigh 18.7°C · Low 11.3°C · 74 mm rain
- Recklinghausen in SeptemberGermany · 22 kmHigh 18.8°C · Low 11.4°C · 74 mm rain
- Iserlohn in SeptemberGermany · 23 kmHigh 17.5°C · Low 10.6°C · 72 mm rain
- Gelsenkirchen in SeptemberGermany · 26 kmHigh 19.0°C · Low 11.6°C · 69 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 Dortmund) is explained once on the Dortmund year overview and on the Sources, method and limits page.
Lünen lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.