Monthly climate guide
Koblenz weather in September
With highs near 20°C (69°F) and lows around 9°C (49°F), September feels mild in Koblenz. Rainfall averages about 55 mm (some rain) and the sky is often cloudy. Daytime highs are 4°C cooler than August and 6°C warmer than October.
What stands out in September
- Skies are at their clearest this time of year.
- It cools down fast from here: October is about 6°C cooler.
- Just 80 km apart, but Koblenz runs about 2°C cooler than Frankfurt this month.
- September brings early autumn to Koblenz.
Avg high
20°C
69°F
Avg low
9°C
49°F
Rainfall
55 mm
some rain
Humidity
73%
relative
Sky
64%
cloud · often cloudy
Koblenz weather by month
Show the monthly averages as a table
| Month | Avg high | Avg low | Rain | Humidity | Cloud cover |
|---|---|---|---|---|---|
| January | 4°C / 38°F | -2°C / 29°F | 75 mm | 94% | 83% |
| February | 5°C / 40°F | -2°C / 28°F | 52 mm | 91% | 75% |
| March | 9°C / 49°F | 0°C / 33°F | 48 mm | 85% | 68% |
| April | 14°C / 58°F | 4°C / 38°F | 42 mm | 79% | 65% |
| May | 18°C / 64°F | 7°C / 45°F | 67 mm | 77% | 69% |
| June | 22°C / 71°F | 11°C / 52°F | 77 mm | 73% | 71% |
| July | 24°C / 76°F | 13°C / 56°F | 72 mm | 67% | 68% |
| August | 25°C / 76°F | 13°C / 56°F | 70 mm | 67% | 66% |
| September | 20°C / 69°F | 9°C / 49°F | 55 mm | 73% | 64% |
| October | 14°C / 58°F | 6°C / 43°F | 63 mm | 85% | 72% |
| November | 8°C / 47°F | 2°C / 36°F | 60 mm | 92% | 77% |
| December | 5°C / 41°F | 0°C / 33°F | 84 mm | 95% | 83% |
What to pack for September
- T-shirts plus a light layer for the evening
- Comfortable trainers or sandals for long walks
- A small travel umbrella, just in case
Is September a good time to visit Koblenz?
Compare the months in the chart above to find your ideal window.
Best time to visit Koblenz →Other Germany cities in September
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Koblenz weather in September. WeatherCompare, 2026 (NASA POWER / ERA5, 2011–2020 monthly averages). https://weathercompare.eu/weather/germany/koblenz/september
<a href="https://weathercompare.eu/weather/germany/koblenz/september">Koblenz weather in September</a> (WeatherCompare)
<iframe src="https://weathercompare.eu/embed/germany/koblenz" width="300" height="160" style="border:0;border-radius:12px" loading="lazy" title="Koblenz weather in September"></iframe> <p style="font-size:12px"><a href="https://weathercompare.eu/weather/germany/koblenz/september">Koblenz weather in September</a> – WeatherCompare</p>
Koblenz in September: quick answers
Is September a good time to visit Koblenz?
Yes. September is one of the best months for Koblenz, with highs around 20°C and about 55 mm of rain.
How warm is Koblenz in September?
Average highs are about 20°C (69°F) and average lows about 9°C (49°F), based on 10 years of daily data.
Does it rain a lot in Koblenz in September?
Koblenz typically gets around 55 mm of rain in September — some rain.
Figures are long-term averages for the area around Koblenz (NASA POWER / ERA5, 2011–2020), not a forecast for a specific year. For upcoming days, see the live multi-source forecast.