Click on a day for an hourly weather forecast
The temperatures in Romanshorn in September are usually low and can range between 11°C and 20°C.
You can expect about 3 to 8 days of rain in Romanshorn 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 Romanshorn in September 2026.
If you’re planning to visit Romanshorn in the near future, we highly recommend that you review the 14 day weather forecast for Romanshorn before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 4° / -2° | 11 | 17 | 3 | 32 mm | Awful | Romanshorn in January |
| February | 5° / -2° | 8 | 18 | 3 | 22 mm | Awful | Romanshorn in February |
| March | 10° / 1° | 6 | 23 | 1 | 23 mm | Ok | Romanshorn in March |
| April | 15° / 4° | 6 | 24 | 0 | 24 mm | Good | Romanshorn in April |
| May | 18° / 8° | 10 | 21 | 0 | 45 mm | Good | Romanshorn in May |
| June | 22° / 12° | 10 | 20 | 0 | 54 mm | Ok | Romanshorn in June |
| July | 24° / 14° | 9 | 22 | 0 | 48 mm | Perfect | Romanshorn in July |
| August | 24° / 14° | 8 | 23 | 0 | 48 mm | Perfect | Romanshorn in August |
| September | 20° / 11° | 6 | 24 | 0 | 32 mm | Good | Romanshorn in September |
| October | 15° / 7° | 6 | 25 | 0 | 33 mm | Good | Romanshorn in October |
| November | 9° / 3° | 6 | 23 | 1 | 26 mm | Ok | Romanshorn in November |
| December | 5° / -1° | 11 | 16 | 4 | 35 mm | Awful | Romanshorn in December |