Afton, Wyoming has a Subarctic With Cool Summers And Year Around Rainfall climate (Köppen classification: Dfc). Average annual temperatures range from 25 °F (low) to 53.2 °F (high). Annual precipitation averages 18.1 Inches. Afton is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around Jun. 11 - Jun. 20 through the first frost around Aug. 1 - Aug. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.1 °F | 28.3 °F | 1.46 in. |
| February | 8.2 °F | 32.1 °F | 1.31 in. |
| March | 16.6 °F | 41.3 °F | 1.57 in. |
| April | 25.1 °F | 49.7 °F | 1.83 in. |
| May | 33.1 °F | 60.5 °F | 2.48 in. |
| June | 38.2 °F | 70.3 °F | 1.55 in. |
| July | 43.7 °F | 80.4 °F | 1.04 in. |
| August | 42.4 °F | 79.9 °F | 1.06 in. |
| September | 34.6 °F | 70.3 °F | 1.3 in. |
| October | 26.7 °F | 55.7 °F | 1.6 in. |
| November | 17.4 °F | 40.6 °F | 1.38 in. |
| December | 7.6 °F | 28.7 °F | 1.47 in. |
| Annual | 25 °F | 53.2 °F | 18.05 in. |
| Average First Frost Date | Aug. 1 - Aug. 10 |
| Average Last Frost Date | Jun. 11 - Jun. 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfc - Subarctic With Cool Summers And Year Around Rainfall |