Weir, Mississippi has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 51.8 °F (low) to 74.2 °F (high). Annual precipitation averages 57.5 Inches. Weir 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 | 33.3 °F | 54.4 °F | 5.15 in. |
| February | 36.1 °F | 58.9 °F | 5.28 in. |
| March | 43.0 °F | 67.0 °F | 5.47 in. |
| April | 50.7 °F | 74.8 °F | 5.94 in. |
| May | 59.7 °F | 82.0 °F | 4.68 in. |
| June | 67.2 °F | 88.3 °F | 4.46 in. |
| July | 70.4 °F | 90.8 °F | 4.74 in. |
| August | 69.3 °F | 90.4 °F | 4.33 in. |
| September | 63.2 °F | 85.9 °F | 3.83 in. |
| October | 51.6 °F | 76.4 °F | 3.69 in. |
| November | 41.0 °F | 64.9 °F | 4.43 in. |
| December | 35.7 °F | 56.6 °F | 5.49 in. |
| Annual | 51.8 °F | 74.2 °F | 57.49 in. |
| 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 : 10°F to 15°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |