Climate averages 1991–2020
Troisdorf weather
in September.
A mild, moderately wet month: the 4th warmest and the joint 4th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Troisdorf: daytime highs average 19.2°C and nights cool to about 11.5°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 68 mm of rain on roughly 11 days, which makes September a moderately wet month (the joint 4th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 41 min on an average September day.
The nearest other city in this atlas is Bonn (9 km away). In September its highs average 19.3°C, about as warm as Troisdorf, with 62 mm of rain.
Among the 120 cities listed in Germany, Troisdorf ranks joint 25th of 120 for the warmest September highs and 83rd of 120 for the driest September (rainfall, lowest first). The mean September high of those 120 cities is 18.8°C; Troisdorf is 0.4°C warmer than that mean.
From September to October, average highs fall by 4.8°C to 14.4°C, and monthly rainfall rises from 68 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
Troisdorf climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 5.2°C0.6°C | 0.6°C | 77 | 14.0 | 8.58 h |
| February | 6.5°C0.6°C | 0.6°C | 65 | 12.1 | 10.010 h |
| March | 10.1°C2.5°C | 2.5°C | 68 | 13.6 | 11.812 h |
| April | 14.4°C5.3°C | 5.3°C | 53 | 10.9 | 13.814 h |
| May | 18.1°C9.3°C | 9.3°C | 64 | 11.9 | 15.515 h |
| June | 21.1°C12.5°C | 12.5°C | 73 | 11.8 | 16.416 h |
| July | 23.2°C14.7°C | 14.7°C | 77 | 13.0 | 16.016 h |
| August | 23.0°C14.6°C | 14.6°C | 81 | 12.3 | 14.515 h |
| September, selected | 19.2°C11.5°C | 11.5°C | 68 | 11.0 | 12.713 h |
| October | 14.4°C8.2°C | 8.2°C | 74 | 12.2 | 10.811 h |
| November | 9.2°C4.5°C | 4.5°C | 76 | 13.5 | 9.09 h |
| December | 5.8°C1.6°C | 1.6°C | 90 | 15.5 | 8.08 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
- Bonn in SeptemberGermany · 9 kmHigh 19.3°C · Low 11.5°C · 62 mm rain
- Bergisch Gladbach in SeptemberGermany · 20 kmHigh 18.9°C · Low 11.5°C · 80 mm rain
- Köln in SeptemberGermany · 20 kmHigh 19.1°C · Low 11.4°C · 71 mm rain
- Leverkusen in SeptemberGermany · 27 kmHigh 19.2°C · Low 11.7°C · 71 mm rain
- Solingen in SeptemberGermany · 41 kmHigh 18.0°C · Low 11.0°C · 80 mm rain
- Remscheid in SeptemberGermany · 41 kmHigh 17.2°C · Low 10.2°C · 86 mm rain
- Düren in SeptemberGermany · 46 kmHigh 18.7°C · Low 11.1°C · 61 mm rain
- Wuppertal in SeptemberGermany · 50 kmHigh 18.4°C · Low 11.3°C · 86 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 Troisdorf) is explained once on the Troisdorf year overview and on the Sources, method and limits page.