Prospect, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.1 °C (low) to 15.1 °C (high). Annual precipitation averages 1383 Millimeters. Prospect 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 | -8.2 °C | 1.4 °C | 103.63 mm |
| February | -7.3 °C | 2.9 °C | 89.66 mm |
| March | -3.1 °C | 7.3 °C | 130.3 mm |
| April | 2.6 °C | 14.6 °C | 111 mm |
| May | 8.2 °C | 20.7 °C | 114.81 mm |
| June | 13.3 °C | 25.2 °C | 116.84 mm |
| July | 16.2 °C | 27.9 °C | 111.76 mm |
| August | 15.5 °C | 26.9 °C | 108.71 mm |
| September | 11.6 °C | 23 °C | 120.9 mm |
| October | 5.4 °C | 16.5 °C | 143 mm |
| November | 0.2 °C | 10.1 °C | 111.76 mm |
| December | -4.8 °C | 4.1 °C | 120.65 mm |
| Annual | 4.1 °C | 15.1 °C | 1383.02 mm |
| 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 : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |