State Line, Mississippi has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 12 °C (low) to 25 °C (high). Annual precipitation averages 1544.3 Millimeters. State Line 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. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.2 °C | 15.1 °C | 159.26 mm |
| February | 4.1 °C | 17.7 °C | 133.6 mm |
| March | 7.5 °C | 21.7 °C | 142.49 mm |
| April | 11.3 °C | 25.3 °C | 114.55 mm |
| May | 16.1 °C | 29.1 °C | 112.78 mm |
| June | 20.1 °C | 32 °C | 152.91 mm |
| July | 21.4 °C | 33.1 °C | 140.46 mm |
| August | 21.4 °C | 32.9 °C | 136.14 mm |
| September | 18.7 °C | 30.7 °C | 110.74 mm |
| October | 12 °C | 25.8 °C | 79.76 mm |
| November | 6.3 °C | 20.4 °C | 117.09 mm |
| December | 3.4 °C | 16.3 °C | 144.53 mm |
| Annual | 12 °C | 25 °C | 1544.31 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| 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 |