Hamden, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.2 °F (low) to 60.7 °F (high). Annual precipitation averages 51.9 Inches. Hamden is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 19.7 °F | 36.7 °F | 3.87 in. |
| February | 21.0 °F | 39.3 °F | 3.4 in. |
| March | 28.2 °F | 47.0 °F | 4.45 in. |
| April | 38.3 °F | 59.0 °F | 4.39 in. |
| May | 48.2 °F | 69.9 °F | 4.16 in. |
| June | 57.7 °F | 78.3 °F | 4.59 in. |
| July | 63.3 °F | 83.9 °F | 4.19 in. |
| August | 61.8 °F | 82.0 °F | 4.16 in. |
| September | 54.6 °F | 75.4 °F | 4.65 in. |
| October | 42.8 °F | 63.5 °F | 5.36 in. |
| November | 33.2 °F | 52.0 °F | 3.99 in. |
| December | 25.5 °F | 41.8 °F | 4.65 in. |
| Annual | 41.2 °F | 60.7 °F | 51.86 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |