Fairfield, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 44.1 °F (low) to 61 °F (high). Annual precipitation averages 49.7 Inches. Fairfield is located in USDA Plant Hardiness Zone 7a. 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 | 22.7 °F | 38.3 °F | 3.81 in. |
| February | 23.9 °F | 40.3 °F | 3.06 in. |
| March | 30.8 °F | 47.4 °F | 4.29 in. |
| April | 40.6 °F | 58.8 °F | 4.12 in. |
| May | 50.3 °F | 68.4 °F | 3.91 in. |
| June | 59.9 °F | 77.8 °F | 4.83 in. |
| July | 66.0 °F | 83.3 °F | 3.56 in. |
| August | 65.0 °F | 81.6 °F | 4.32 in. |
| September | 57.8 °F | 75.5 °F | 4.65 in. |
| October | 46.8 °F | 64.2 °F | 4.63 in. |
| November | 36.8 °F | 53.4 °F | 4.06 in. |
| December | 28.9 °F | 43.4 °F | 4.47 in. |
| Annual | 44.1 °F | 61 °F | 49.71 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 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |