Ralston, Wyoming has a Cold Desert Climate climate (Köppen classification: BWk). Average annual temperatures range from 0.3 °C (low) to 14.9 °C (high). Annual precipitation averages 195.1 Millimeters. Ralston is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.5 °C | 1.3 °C | 5.08 mm |
| February | -9.7 °C | 3.3 °C | 5.59 mm |
| March | -4.7 °C | 9.7 °C | 7.87 mm |
| April | -0.3 °C | 14.3 °C | 18.29 mm |
| May | 4.9 °C | 19.3 °C | 38.1 mm |
| June | 9.4 °C | 25.1 °C | 33.78 mm |
| July | 12.8 °C | 29.9 °C | 24.64 mm |
| August | 11.7 °C | 29.2 °C | 13.72 mm |
| September | 6.8 °C | 23.4 °C | 20.07 mm |
| October | 0.4 °C | 15.1 °C | 17.02 mm |
| November | -5.8 °C | 7.1 °C | 6.35 mm |
| December | -10.6 °C | 1.5 °C | 4.57 mm |
| Annual | 0.3 °C | 14.9 °C | 195.08 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BWk - Cold Desert Climate |