Glenham, South Dakota has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 33.5 °F (low) to 56 °F (high). Annual precipitation averages 17.9 Inches. 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 | 5.1 °F | 24.1 °F | 0.34 in. |
| February | 8.4 °F | 28.8 °F | 0.48 in. |
| March | 19.7 °F | 41.6 °F | 0.68 in. |
| April | 31.6 °F | 56.0 °F | 1.39 in. |
| May | 44.2 °F | 67.9 °F | 2.76 in. |
| June | 55.2 °F | 78.0 °F | 3.25 in. |
| July | 60.9 °F | 85.4 °F | 2.65 in. |
| August | 58.2 °F | 83.9 °F | 2.16 in. |
| September | 48.9 °F | 75.0 °F | 1.6 in. |
| October | 35.5 °F | 58.4 °F | 1.69 in. |
| November | 22.4 °F | 42.8 °F | 0.45 in. |
| December | 11.3 °F | 29.5 °F | 0.4 in. |
| Annual | 33.5 °F | 56 °F | 17.85 in. |
| 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 : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |