Monticello, Kentucky has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.4 °C (low) to 19.7 °C (high). Annual precipitation averages 1329.2 Millimeters. Monticello is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.6 °C | 7.1 °C | 115.82 mm |
| February | -2.1 °C | 9.4 °C | 99.06 mm |
| March | 1.6 °C | 14.4 °C | 127.51 mm |
| April | 6.6 °C | 20.2 °C | 118.87 mm |
| May | 12.1 °C | 24.7 °C | 131.83 mm |
| June | 16.5 °C | 28.7 °C | 121.92 mm |
| July | 18.6 °C | 30.3 °C | 124.71 mm |
| August | 17.7 °C | 30.1 °C | 96.01 mm |
| September | 13.8 °C | 27.1 °C | 94.49 mm |
| October | 7.4 °C | 21.3 °C | 76.96 mm |
| November | 1.6 °C | 14.5 °C | 90.93 mm |
| December | -1.4 °C | 9.1 °C | 131.06 mm |
| Annual | 7.4 °C | 19.7 °C | 1329.17 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |