Monticello, Utah has a Humid Continental Climate - Dry Warm Summer climate (Köppen classification: Dsa). Average annual temperatures range from 1.5 °C (low) to 15.3 °C (high). Annual precipitation averages 415.1 Millimeters. Monticello is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.5 °C | 2.4 °C | 36.83 mm |
| February | -6.8 °C | 4.6 °C | 34.8 mm |
| March | -3.3 °C | 9.9 °C | 30.48 mm |
| April | -0.4 °C | 14.1 °C | 33.53 mm |
| May | 4.1 °C | 19.6 °C | 24.64 mm |
| June | 9.2 °C | 26.2 °C | 12.7 mm |
| July | 13.1 °C | 28.9 °C | 38.61 mm |
| August | 12.6 °C | 27.2 °C | 45.47 mm |
| September | 8.3 °C | 23 °C | 44.2 mm |
| October | 2 °C | 16 °C | 42.93 mm |
| November | -3.9 °C | 8.8 °C | 31.24 mm |
| December | -8.4 °C | 2.8 °C | 39.62 mm |
| Annual | 1.5 °C | 15.3 °C | 415.05 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dsa - Humid Continental Climate - Dry Warm Summer |