Lebanon, South Dakota has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 33.1 °F (low) to 55.7 °F (high). Annual precipitation averages 20.4 Inches. Lebanon 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 | 5.4 °F | 24.3 °F | 0.39 in. |
| February | 9.1 °F | 28.9 °F | 0.59 in. |
| March | 19.8 °F | 41.5 °F | 0.84 in. |
| April | 31.5 °F | 55.7 °F | 1.84 in. |
| May | 43.7 °F | 67.8 °F | 3.09 in. |
| June | 54.4 °F | 78.0 °F | 3.49 in. |
| July | 59.6 °F | 84.4 °F | 2.94 in. |
| August | 57.7 °F | 83.3 °F | 2.43 in. |
| September | 48.2 °F | 74.5 °F | 1.94 in. |
| October | 34.8 °F | 58.5 °F | 1.79 in. |
| November | 21.8 °F | 42.3 °F | 0.59 in. |
| December | 10.6 °F | 28.8 °F | 0.48 in. |
| Annual | 33.1 °F | 55.7 °F | 20.41 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 |