Glenham, South Dakota has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 0.8 °C (low) to 13.3 °C (high). Annual precipitation averages 453.4 Millimeters. Glenham is located in USDA Plant Hardiness Zone 4b. 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 | -14.9 °C | -4.4 °C | 8.64 mm |
| February | -13.1 °C | -1.8 °C | 12.19 mm |
| March | -6.8 °C | 5.3 °C | 17.27 mm |
| April | -0.2 °C | 13.3 °C | 35.31 mm |
| May | 6.8 °C | 19.9 °C | 70.1 mm |
| June | 12.9 °C | 25.6 °C | 82.55 mm |
| July | 16.1 °C | 29.7 °C | 67.31 mm |
| August | 14.6 °C | 28.8 °C | 54.86 mm |
| September | 9.4 °C | 23.9 °C | 40.64 mm |
| October | 1.9 °C | 14.7 °C | 42.93 mm |
| November | -5.3 °C | 6 °C | 11.43 mm |
| December | -11.5 °C | -1.4 °C | 10.16 mm |
| Annual | 0.8 °C | 13.3 °C | 453.39 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 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |