Jeffrey City, Wyoming has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from -1.3 °C (low) to 13.7 °C (high). Annual precipitation averages 247.4 Millimeters. Jeffrey City is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.4 °C | -0.1 °C | 8.89 mm |
| February | -10.8 °C | 1.3 °C | 12.95 mm |
| March | -6.1 °C | 7.1 °C | 19.56 mm |
| April | -2.7 °C | 12.1 °C | 35.56 mm |
| May | 2.2 °C | 17.7 °C | 48.26 mm |
| June | 6.8 °C | 24.7 °C | 23.88 mm |
| July | 10.7 °C | 29.7 °C | 16.76 mm |
| August | 9.9 °C | 28.5 °C | 13.46 mm |
| September | 4.8 °C | 22.7 °C | 20.83 mm |
| October | -1.2 °C | 14.4 °C | 23.88 mm |
| November | -6.6 °C | 5.9 °C | 12.19 mm |
| December | -11.2 °C | 0 °C | 11.18 mm |
| Annual | -1.3 °C | 13.7 °C | 247.4 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |