Glendo, Wyoming has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 0.5 °C (low) to 16.5 °C (high). Annual precipitation averages 313.7 Millimeters. Glendo is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.2 °C | 4.1 °C | 7.11 mm |
| February | -9.2 °C | 5.3 °C | 9.91 mm |
| March | -4.7 °C | 10.6 °C | 18.03 mm |
| April | -0.7 °C | 14.4 °C | 40.89 mm |
| May | 4.7 °C | 19.7 °C | 61.98 mm |
| June | 9.8 °C | 26.2 °C | 48.26 mm |
| July | 13.3 °C | 31.3 °C | 32 mm |
| August | 12 °C | 30.4 °C | 22.35 mm |
| September | 6.5 °C | 25.1 °C | 24.89 mm |
| October | -0.4 °C | 16.9 °C | 27.94 mm |
| November | -5.8 °C | 9.6 °C | 11.18 mm |
| December | -9.9 °C | 4.2 °C | 9.14 mm |
| Annual | 0.5 °C | 16.5 °C | 313.68 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| 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 | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |