| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F |
| 2012 Hardiness Zone: | Zone 4b: -25°F to -20°F |
| 1990 Hardiness Zone: | Zone 4a: -30F to -25F |
| Average First Frost Date: | Oct. 1 - Oct. 10 |
| Average Last Frost Date: | May 11 - May 20 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 83d - St. Lawrence Lowlands |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 13603 - Watertown, NY | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 8 | 10 | 21 | 34 | 46 | 55 | 60 | 59 | 50 | 39 | 30 | 17 | 36 |
| Avg Max Temp (°F) | 28 | 31 | 40 | 53 | 66 | 75 | 80 | 78 | 70 | 57 | 46 | 34 | 55 |
| Avg Precip (In.) | 3.74 | 2.63 | 2.98 | 3.15 | 3.35 | 3.47 | 3.38 | 3.93 | 4.58 | 3.87 | 4.67 | 3.88 | 43.63 |