Average annual temperature is 9.1 °C
Absolute maximum temperature: 31.1 °C
Absolute minimum temperature: -30.0 °C
Number of sunny days: 126 days
Number of rainy days: 204 days
Number of snow days: 35 days
Look at detailed online map of Grand Isle
* Weather data for Grand Isle United States is based on climate observations for 2026 year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Absolute maximum temperature (°C) | 6.2 | 10.1 | 10.0 | 26.0 | 28.2 | 31.1 | 30.5 | 26.8 | 29.2 | 26.2 | 13.3 | 9.5 |
| Average daytime temperature (°C) | 1.0 | 1.2 | 3.8 | 14.2 | 18.8 | 22.9 | 26.4 | 23.5 | 22.1 | 16.2 | 6.3 | 3.7 |
| Average temperature (°C) | -2.1 | -4.4 | -0.1 | 8.2 | 13.2 | 18.2 | 21.9 | 19.5 | 17.8 | 12.6 | 2.5 | 0.7 |
| Average night temperature (°C) | -5.3 | -9.2 | -3.9 | 3.5 | 7.7 | 14.0 | 18.3 | 16.1 | 14.2 | 9.5 | -0.5 | -1.9 |
| Absolute minimum temperature (°C) | -13.5 | -30.0 | -10.4 | -5.5 | 2.3 | 8.6 | 13.5 | 11.6 | 9.0 | 0.0 | -6.3 | -10.2 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 9.0 | 11.0 | 12.0 | 14.0 | 15.0 | 15.0 | 15.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 |
| Daylight mean duration (h) | 9.2 | 10.4 | 11.9 | 13.5 | 14.8 | 15.5 | 15.2 | 14.0 | 12.5 | 11.0 | 9.6 | 8.9 |
| Daylight minimum duration (h) | 8.0 | 9.0 | 11.0 | 12.0 | 14.0 | 15.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 | 8.0 |
| Sunshine mean duration (h) | 2.8 | 5.8 | 5.9 | 7.8 | 11.4 | 10.3 | 10.7 | 10.1 | 9.3 | 6.1 | 5.6 | 3.3 |
| Precipitation (mm) | 101 | 64 | 75 | 104 | 89 | 136 | 214 | 182 | 86 | 111 | 53 | 134 |
| Sunny days | 7 | 8 | 9 | 13 | 17 | 10 | 2 | 6 | 18 | 11 | 13 | 12 |
| Rainy days | 14 | 10 | 17 | 17 | 14 | 20 | 29 | 25 | 12 | 20 | 11 | 15 |
| Snow days | 10 | 10 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 6 | 4 |
The best time to visit Grand Isle during the most sunny months:
Months with the longest average daylight duration in Grand Isle:
The largest precipitation sum in Grand Isle is at