Fort Pierre, South Dakota has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 33.8 °F (low) to 59.3 °F (high). Annual precipitation averages 18.5 Inches. Fort Pierre 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 Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 7.2 °F | 29.9 °F | 0.42 in. |
| February | 10.6 °F | 34.5 °F | 0.49 in. |
| March | 21.0 °F | 46.1 °F | 0.78 in. |
| April | 31.9 °F | 58.1 °F | 1.93 in. |
| May | 44.4 °F | 69.3 °F | 3.05 in. |
| June | 55.3 °F | 79.6 °F | 3.33 in. |
| July | 61.4 °F | 87.8 °F | 2.47 in. |
| August | 58.5 °F | 87.0 °F | 2.14 in. |
| September | 48.7 °F | 77.9 °F | 1.63 in. |
| October | 34.5 °F | 61.6 °F | 1.44 in. |
| November | 21.4 °F | 46.2 °F | 0.41 in. |
| December | 10.7 °F | 33.2 °F | 0.36 in. |
| Annual | 33.8 °F | 59.3 °F | 18.45 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| 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 |