Tolland, Connecticut has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.4 °F (low) to 58.4 °F (high). Annual precipitation averages 49.2 Inches. Tolland is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 17.0 °F | 34.5 °F | 3.45 in. |
| February | 17.8 °F | 37.1 °F | 3.07 in. |
| March | 25.4 °F | 44.8 °F | 4.21 in. |
| April | 35.4 °F | 56.9 °F | 4.17 in. |
| May | 45.2 °F | 67.5 °F | 3.61 in. |
| June | 54.7 °F | 75.7 °F | 4.43 in. |
| July | 60.3 °F | 80.9 °F | 4.03 in. |
| August | 58.5 °F | 79.3 °F | 4.5 in. |
| September | 51.4 °F | 72.6 °F | 4.58 in. |
| October | 40.2 °F | 60.9 °F | 4.94 in. |
| November | 31.2 °F | 50.1 °F | 3.77 in. |
| December | 23.5 °F | 40.2 °F | 4.4 in. |
| Annual | 38.4 °F | 58.4 °F | 49.16 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |