| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 4b: -25°F to -20°F |
| 2012 Hardiness Zone: | Zone 4b: -25°F to -20°F |
| 1990 Hardiness Zone: | Zone 4a: -30F to -25F |
| Average First Frost Date: | Sep. 21 - Sep. 30 |
| Average Last Frost Date: | May 21 - May 31 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 52c - Rochester/Paleozoic Plateau Upland |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 55972 - Saint Charles, MN | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 3 | 10 | 22 | 35 | 46 | 56 | 60 | 58 | 49 | 37 | 24 | 10 | 34 |
| Avg Max Temp (°F) | 22 | 29 | 41 | 56 | 69 | 78 | 82 | 79 | 71 | 59 | 41 | 26 | 54 |
| Avg Precip (In.) | 1.06 | .81 | 1.96 | 3.28 | 3.83 | 4.35 | 4.76 | 4.56 | 3.59 | 2.34 | 2.19 | 1.14 | 33.87 |