Myrtle, Mississippi has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.9 °C (low) to 22.4 °C (high). Annual precipitation averages 1455.4 Millimeters. Myrtle is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -0.8 °C | 10.4 °C | 122.43 mm |
| February | 0.8 °C | 12.9 °C | 123.7 mm |
| March | 4.8 °C | 17.8 °C | 135.38 mm |
| April | 9.3 °C | 22.9 °C | 142.49 mm |
| May | 14.7 °C | 27.1 °C | 133.86 mm |
| June | 19.1 °C | 30.8 °C | 121.16 mm |
| July | 20.9 °C | 32.5 °C | 111.25 mm |
| August | 20 °C | 32.3 °C | 96.52 mm |
| September | 16.3 °C | 29.5 °C | 99.82 mm |
| October | 9.4 °C | 23.8 °C | 98.81 mm |
| November | 3.9 °C | 17 °C | 110.74 mm |
| December | 0.8 °C | 11.9 °C | 159.26 mm |
| Annual | 9.9 °C | 22.4 °C | 1455.42 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |