Jamestown, Rhode Island has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 44.1 °F (low) to 59 °F (high). Annual precipitation averages 47.7 Inches. Jamestown is located in USDA Plant Hardiness Zone 7a. 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 | 23.3 °F | 38.5 °F | 3.95 in. |
| February | 24.6 °F | 40.1 °F | 3.53 in. |
| March | 30.8 °F | 45.7 °F | 5.13 in. |
| April | 39.9 °F | 54.9 °F | 4.53 in. |
| May | 49.4 °F | 64.3 °F | 3.49 in. |
| June | 58.8 °F | 73.1 °F | 3.57 in. |
| July | 65.0 °F | 79.4 °F | 3.05 in. |
| August | 64.1 °F | 79.0 °F | 3.46 in. |
| September | 58.0 °F | 73.0 °F | 3.72 in. |
| October | 47.4 °F | 62.8 °F | 4.5 in. |
| November | 38.1 °F | 53.0 °F | 4.04 in. |
| December | 29.5 °F | 44.2 °F | 4.76 in. |
| Annual | 44.1 °F | 59 °F | 47.73 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 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |