Click on a day for an hourly weather forecast
The temperatures in Mainz in September are comfortable with low of 12°C and and high up to 22°C.
You can expect about 3 to 8 days of rain in Mainz during the month of September. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Mainz in September 2025.
If you’re planning to visit Mainz in the near future, we highly recommend that you review the 14 day weather forecast for Mainz before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 4° / 0° | 6 | 16 | 9 | 44 mm | Awful | Mainz in January |
| February | 6° / 1° | 5 | 17 | 6 | 40 mm | Awful | Mainz in February |
| March | 11° / 3° | 5 | 24 | 2 | 33 mm | Bad | Mainz in March |
| April | 17° / 6° | 4 | 25 | 1 | 34 mm | Good | Mainz in April |
| May | 20° / 9° | 6 | 25 | 0 | 84 mm | Good | Mainz in May |
| June | 24° / 13° | 5 | 25 | 0 | 74 mm | Perfect | Mainz in June |
| July | 26° / 15° | 5 | 26 | 0 | 84 mm | Perfect | Mainz in July |
| August | 26° / 15° | 4 | 27 | 0 | 67 mm | Perfect | Mainz in August |
| September | 22° / 12° | 3 | 27 | 0 | 45 mm | Good | Mainz in September |
| October | 15° / 8° | 4 | 27 | 0 | 50 mm | Good | Mainz in October |
| November | 10° / 4° | 5 | 23 | 2 | 49 mm | Bad | Mainz in November |
| December | 6° / 2° | 8 | 18 | 6 | 59 mm | Awful | Mainz in December |