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The weather in Aosta in September is very cold with temperatures between 0°C and 13°C, warm clothes are a must.
You can expect rain for roughly half of the month of September in Aosta. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
You can expect a few days of snow in Aosta during September. It’s important to get out your snow boots and warm mittens to stay warm while you explore Aosta.
Our weather forecast can give you a great sense of what weather to expect in Aosta in September 2025.
If you’re planning to visit Aosta in the near future, we highly recommend that you review the 14 day weather forecast for Aosta before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -4° / -16° | 2 | 8 | 21 | 116 mm | Awful | Aosta in January |
| February | -3° / -16° | 3 | 5 | 21 | 114 mm | Awful | Aosta in February |
| March | 0° / -13° | 6 | 4 | 23 | 127 mm | Awful | Aosta in March |
| April | 4° / -8° | 9 | 3 | 20 | 185 mm | Awful | Aosta in April |
| May | 8° / -4° | 18 | 4 | 12 | 272 mm | Awful | Aosta in May |
| June | 14° / 0° | 19 | 10 | 2 | 249 mm | Bad | Aosta in June |
| July | 17° / 2° | 16 | 14 | 1 | 219 mm | Ok | Aosta in July |
| August | 17° / 2° | 15 | 16 | 0 | 201 mm | Ok | Aosta in August |
| September | 13° / 0° | 12 | 16 | 3 | 129 mm | Awful | Aosta in September |
| October | 8° / -5° | 7 | 17 | 8 | 126 mm | Awful | Aosta in October |
| November | 2° / -10° | 4 | 9 | 17 | 183 mm | Awful | Aosta in November |
| December | -3° / -15° | 1 | 11 | 18 | 101 mm | Awful | Aosta in December |