Jamestown, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 11.9 °C (low) to 24.7 °C (high). Annual precipitation averages 1422.4 Millimeters. Jamestown is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.7 °C | 13.9 °C | 139.45 mm |
| February | 3.4 °C | 16.3 °C | 128.27 mm |
| March | 7.2 °C | 20.5 °C | 135.64 mm |
| April | 11.2 °C | 24.6 °C | 131.32 mm |
| May | 16.4 °C | 28.6 °C | 116.84 mm |
| June | 20.7 °C | 32.2 °C | 113.28 mm |
| July | 22.2 °C | 33.9 °C | 94.74 mm |
| August | 21.8 °C | 34.3 °C | 86.87 mm |
| September | 18.1 °C | 31.4 °C | 97.28 mm |
| October | 11.6 °C | 25.9 °C | 113.54 mm |
| November | 6.1 °C | 19.6 °C | 121.67 mm |
| December | 2.7 °C | 15.1 °C | 143.51 mm |
| Annual | 11.9 °C | 24.7 °C | 1422.41 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |