| 2023 Hardiness Zone: | Zone 4b: -25°F to -20°F Zone 4a: -30°F to -25°F | |
| 2012 Hardiness Zone: | Zone 4b: -25°F to -20°F Zone 4a: -30°F to -25°F | |
| 1990 Hardiness Zone: | Zone 4a: -30F to -25F | |
| Average First Frost Date: | Sep. 21 - Sep. 30 | |
| Average Last Frost Date: | May 11 - May 20 | |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year | |
| Ecoregion: | 46m - Big Sioux Basin | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 57201 - Watertown, SD | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 0 | 7 | 19 | 32 | 44 | 54 | 59 | 56 | 46 | 34 | 19 | 6 | 31 |
| Avg Max Temp (°F) | 20 | 27 | 39 | 55 | 68 | 78 | 83 | 80 | 71 | 58 | 38 | 25 | 53 |
| Avg Precip (In.) | .6 | .51 | 1.34 | 2.01 | 2.74 | 3.92 | 3.01 | 2.86 | 2.04 | 1.91 | .96 | .41 | 22.31 |