Average annual temperature is 9.4 °C
Absolute maximum temperature: 30.9 °C
Absolute minimum temperature: -29.2 °C
Number of sunny days: 130 days
Number of rainy days: 197 days
Number of snow days: 38 days
Look at detailed online map of Grand Isle County
* Weather data for Grand Isle County 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) | 7.5 | 8.2 | 7.8 | 22.6 | 27.6 | 30.9 | 27.1 | 24.3 | 27.7 | 24.7 | 12.5 | 9.3 |
| Average daytime temperature (°C) | 1.0 | 0.8 | 2.8 | 12.7 | 17.6 | 21.9 | 24.5 | 22.6 | 21.7 | 15.6 | 6.8 | 4.3 |
| Average temperature (°C) | -1.7 | -4.1 | -0.2 | 7.5 | 12.4 | 18.0 | 21.7 | 20.1 | 19.0 | 13.4 | 3.8 | 1.8 |
| Average night temperature (°C) | -4.0 | -8.0 | -2.9 | 3.4 | 8.0 | 14.9 | 19.9 | 18.2 | 16.8 | 11.6 | 1.9 | -0.1 |
| Absolute minimum temperature (°C) | -11.8 | -29.2 | -7.9 | -5.3 | 2.9 | 9.0 | 15.5 | 13.4 | 12.0 | 2.1 | -4.4 | -7.4 |
| 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) | 2.7 | 5.6 | 5.9 | 7.8 | 11.3 | 10.3 | 10.5 | 10.2 | 9.2 | 6.3 | 5.3 | 3.4 |
| Precipitation (mm) | 109 | 68 | 73 | 88 | 61 | 111 | 183 | 153 | 79 | 183 | 74 | 148 |
| Sunny days | 5 | 8 | 11 | 13 | 20 | 12 | 7 | 8 | 17 | 8 | 10 | 11 |
| Rainy days | 12 | 12 | 13 | 17 | 11 | 18 | 24 | 23 | 13 | 23 | 16 | 15 |
| Snow days | 14 | 8 | 7 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 4 | 5 |
The best time to visit Grand Isle County during the most sunny months:
Months with the longest average daylight duration in Grand Isle County:
The largest precipitation sum in Grand Isle County is at