Simmesport, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 13.7 °C (low) to 25.3 °C (high). Annual precipitation averages 1538.5 Millimeters. Simmesport is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4.1 °C | 15.6 °C | 165.61 mm |
| February | 6.1 °C | 17.9 °C | 128.52 mm |
| March | 9.6 °C | 21.9 °C | 120.4 mm |
| April | 13.3 °C | 25.3 °C | 131.57 mm |
| May | 18 °C | 28.9 °C | 127.25 mm |
| June | 21.6 °C | 32 °C | 138.68 mm |
| July | 22.7 °C | 33.1 °C | 120.14 mm |
| August | 22.3 °C | 33.3 °C | 118.62 mm |
| September | 19.7 °C | 31 °C | 111 mm |
| October | 13.7 °C | 26.6 °C | 105.92 mm |
| November | 7.9 °C | 20.9 °C | 131.06 mm |
| December | 5.2 °C | 16.9 °C | 139.7 mm |
| Annual | 13.7 °C | 25.3 °C | 1538.47 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |