Monticello, Mississippi has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 54.3 °F (low) to 78 °F (high). Annual precipitation averages 60.5 Inches. Monticello is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 36.4 °F | 59.2 °F | 6.02 in. |
| February | 39.8 °F | 64.2 °F | 5.78 in. |
| March | 46.3 °F | 71.3 °F | 5.77 in. |
| April | 53.5 °F | 78.6 °F | 5.37 in. |
| May | 61.9 °F | 85.4 °F | 4.74 in. |
| June | 69.0 °F | 91.1 °F | 4.94 in. |
| July | 71.4 °F | 93.3 °F | 5.42 in. |
| August | 71.0 °F | 93.5 °F | 4.92 in. |
| September | 66.1 °F | 89.0 °F | 3.81 in. |
| October | 54.3 °F | 80.0 °F | 3.67 in. |
| November | 43.5 °F | 69.0 °F | 4.66 in. |
| December | 38.8 °F | 61.6 °F | 5.36 in. |
| Annual | 54.3 °F | 78 °F | 60.46 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 30-40 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |