Click on a day for an hourly weather forecast
The temperatures in Blenheim in September are comfortable with low of 14°C and and high up to 22°C.
You can expect about 3 to 8 days of rain in Blenheim 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 Blenheim in September 2025.
If you’re planning to visit Blenheim in the near future, we highly recommend that you review the 14 day weather forecast for Blenheim before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -2° / -7° | 6 | 7 | 18 | 73 mm | Awful | Blenheim in January |
| February | -1° / -7° | 5 | 8 | 16 | 78 mm | Awful | Blenheim in February |
| March | 5° / -2° | 7 | 14 | 10 | 87 mm | Awful | Blenheim in March |
| April | 10° / 3° | 10 | 16 | 4 | 140 mm | Awful | Blenheim in April |
| May | 18° / 9° | 8 | 23 | 0 | 147 mm | Ok | Blenheim in May |
| June | 23° / 14° | 8 | 23 | 0 | 162 mm | Good | Blenheim in June |
| July | 26° / 18° | 8 | 23 | 0 | 153 mm | Good | Blenheim in July |
| August | 25° / 17° | 7 | 24 | 0 | 127 mm | Good | Blenheim in August |
| September | 22° / 14° | 6 | 24 | 0 | 100 mm | Good | Blenheim in September |
| October | 15° / 9° | 7 | 23 | 1 | 110 mm | Ok | Blenheim in October |
| November | 8° / 3° | 6 | 18 | 6 | 75 mm | Bad | Blenheim in November |
| December | 2° / -2° | 7 | 11 | 14 | 73 mm | Awful | Blenheim in December |