French Island, Wisconsin has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.7 °C (low) to 13.9 °C (high). Annual precipitation averages 933.2 Millimeters. French Island is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -12.1 °C | -3.1 °C | 29.97 mm |
| February | -10.2 °C | -0.4 °C | 29.97 mm |
| March | -3.8 °C | 6.3 °C | 51.31 mm |
| April | 3.2 °C | 14.3 °C | 101.6 mm |
| May | 9.7 °C | 21.3 °C | 121.92 mm |
| June | 15.5 °C | 26.6 °C | 132.59 mm |
| July | 17.8 °C | 28.6 °C | 107.95 mm |
| August | 16.6 °C | 27.5 °C | 104.14 mm |
| September | 12.1 °C | 23.3 °C | 96.01 mm |
| October | 5.2 °C | 15.8 °C | 71.37 mm |
| November | -1.4 °C | 7.1 °C | 48.77 mm |
| December | -8.1 °C | -0.2 °C | 37.59 mm |
| Annual | 3.7 °C | 13.9 °C | 933.19 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |