North Granby, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 38.7 °F (low) to 59.4 °F (high). Annual precipitation averages 52.3 Inches. North Granby is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 16.1 °F | 34.0 °F | 3.64 in. |
| February | 17.3 °F | 36.9 °F | 3.27 in. |
| March | 25.4 °F | 45.1 °F | 4.33 in. |
| April | 36.1 °F | 58.6 °F | 4.07 in. |
| May | 46.7 °F | 69.8 °F | 3.98 in. |
| June | 56.0 °F | 78.0 °F | 4.86 in. |
| July | 61.3 °F | 83.2 °F | 4.46 in. |
| August | 59.5 °F | 81.3 °F | 4.35 in. |
| September | 51.9 °F | 74.2 °F | 4.76 in. |
| October | 40.5 °F | 61.7 °F | 5.57 in. |
| November | 31.1 °F | 50.1 °F | 4.01 in. |
| December | 22.6 °F | 39.3 °F | 4.96 in. |
| Annual | 38.7 °F | 59.4 °F | 52.26 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |