| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F | |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 6a: -10F to -5F | |
| Average First Frost Date: | Oct. 11 - Oct. 20 | |
| Average Last Frost Date: | May 1 - May 10 | |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers | |
| Ecoregion: | 59a - Connecticut Valley | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 01077 - Southwick, MA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 15 | 17 | 26 | 37 | 47 | 56 | 61 | 60 | 51 | 40 | 32 | 22 | 39 |
| Avg Max Temp (°F) | 34 | 37 | 47 | 59 | 71 | 79 | 84 | 82 | 74 | 63 | 51 | 39 | 60 |
| Avg Precip (In.) | 4.03 | 3.08 | 4.11 | 4.27 | 4.35 | 4.03 | 4.06 | 4.33 | 4.19 | 4.28 | 4.18 | 3.88 | 48.79 |