Click on a day for an hourly weather forecast
The temperatures in Hamilton in September are quite cold with temperatures between 6°C and 15°C, warm clothes are a must.
You can expect about 3 to 8 days of rain in Hamilton 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 Hamilton in September 2025.
If you’re planning to visit Hamilton in the near future, we highly recommend that you review the 14 day weather forecast for Hamilton before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 24° / 13° | 5 | 26 | 0 | 74 mm | Perfect | Hamilton in January |
| February | 24° / 13° | 4 | 24 | 0 | 86 mm | Perfect | Hamilton in February |
| March | 22° / 12° | 3 | 28 | 0 | 67 mm | Good | Hamilton in March |
| April | 20° / 10° | 5 | 25 | 0 | 83 mm | Good | Hamilton in April |
| May | 16° / 8° | 6 | 26 | 0 | 98 mm | Good | Hamilton in May |
| June | 14° / 7° | 6 | 24 | 0 | 93 mm | Good | Hamilton in June |
| July | 13° / 5° | 5 | 26 | 0 | 93 mm | Ok | Hamilton in July |
| August | 14° / 6° | 6 | 25 | 0 | 95 mm | Good | Hamilton in August |
| September | 15° / 6° | 7 | 23 | 0 | 107 mm | Ok | Hamilton in September |
| October | 17° / 8° | 5 | 26 | 0 | 97 mm | Good | Hamilton in October |
| November | 20° / 9° | 7 | 23 | 0 | 89 mm | Ok | Hamilton in November |
| December | 22° / 12° | 7 | 24 | 0 | 94 mm | Ok | Hamilton in December |