Monticello, Utah has a Humid Continental Climate - Dry Warm Summer climate (Köppen classification: Dsa). Average annual temperatures range from 34.7 °F (low) to 59.5 °F (high). Annual precipitation averages 16.3 Inches. 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 | 16.7 °F | 36.3 °F | 1.45 in. |
| February | 19.7 °F | 40.2 °F | 1.37 in. |
| March | 26.0 °F | 49.9 °F | 1.2 in. |
| April | 31.3 °F | 57.3 °F | 1.32 in. |
| May | 39.4 °F | 67.2 °F | 0.97 in. |
| June | 48.6 °F | 79.1 °F | 0.5 in. |
| July | 55.5 °F | 84.1 °F | 1.52 in. |
| August | 54.6 °F | 81.0 °F | 1.79 in. |
| September | 46.9 °F | 73.4 °F | 1.74 in. |
| October | 35.6 °F | 60.8 °F | 1.69 in. |
| November | 25.0 °F | 47.8 °F | 1.23 in. |
| December | 16.8 °F | 37.1 °F | 1.56 in. |
| Annual | 34.7 °F | 59.5 °F | 16.34 in. |
| 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 : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dsa - Humid Continental Climate - Dry Warm Summer |