Plymouth, Utah has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.1 °F (low) to 60.3 °F (high). Annual precipitation averages 15 Inches. Plymouth is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 15.5 °F | 32.6 °F | 1.77 in. |
| February | 19.2 °F | 37.7 °F | 1.45 in. |
| March | 28.2 °F | 49.4 °F | 1.53 in. |
| April | 34.2 °F | 58.6 °F | 1.36 in. |
| May | 41.7 °F | 67.9 °F | 1.94 in. |
| June | 48.4 °F | 79.0 °F | 0.86 in. |
| July | 55.9 °F | 89.3 °F | 0.47 in. |
| August | 54.6 °F | 88.2 °F | 0.59 in. |
| September | 45.7 °F | 77.5 °F | 1.24 in. |
| October | 34.8 °F | 62.4 °F | 1.37 in. |
| November | 25.4 °F | 46.8 °F | 0.96 in. |
| December | 17.0 °F | 34.0 °F | 1.46 in. |
| Annual | 35.1 °F | 60.3 °F | 15 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 | Dfb - Humid Continental Mild Summer, Wet All Year |