| 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 Zone 4a: -30°F to -25°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 13691 - Theresa, NY | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 7 | 10 | 20 | 33 | 44 | 53 | 58 | 57 | 48 | 37 | 29 | 16 | 34 |
| Avg Max Temp (°F) | 28 | 31 | 41 | 54 | 67 | 76 | 81 | 79 | 70 | 58 | 46 | 33 | 55 |
| Avg Precip (In.) | 3.36 | 2.41 | 2.77 | 3.08 | 3.25 | 3.38 | 3.27 | 3.82 | 4.41 | 3.64 | 4.24 | 3.55 | 41.19 |