Newtown, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.2 °F (low) to 60.3 °F (high). Annual precipitation averages 51.5 Inches. Newtown 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 | 18.5 °F | 36.0 °F | 3.92 in. |
| February | 19.9 °F | 38.8 °F | 3.14 in. |
| March | 27.1 °F | 46.7 °F | 4.37 in. |
| April | 37.5 °F | 59.2 °F | 4.11 in. |
| May | 47.6 °F | 70.2 °F | 3.96 in. |
| June | 56.9 °F | 78.5 °F | 4.71 in. |
| July | 62.4 °F | 83.6 °F | 4.53 in. |
| August | 60.8 °F | 81.6 °F | 4.62 in. |
| September | 53.5 °F | 74.5 °F | 4.66 in. |
| October | 41.8 °F | 62.8 °F | 4.86 in. |
| November | 32.2 °F | 51.4 °F | 4.18 in. |
| December | 24.4 °F | 40.8 °F | 4.45 in. |
| Annual | 40.2 °F | 60.3 °F | 51.51 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 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 |