Fort Pierre, South Dakota has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 1 °C (low) to 15.1 °C (high). Annual precipitation averages 468.6 Millimeters. 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 | -13.8 °C | -1.2 °C | 10.67 mm |
| February | -11.9 °C | 1.4 °C | 12.45 mm |
| March | -6.1 °C | 7.8 °C | 19.81 mm |
| April | -0.1 °C | 14.5 °C | 49.02 mm |
| May | 6.9 °C | 20.7 °C | 77.47 mm |
| June | 12.9 °C | 26.4 °C | 84.58 mm |
| July | 16.3 °C | 31 °C | 62.74 mm |
| August | 14.7 °C | 30.6 °C | 54.36 mm |
| September | 9.3 °C | 25.5 °C | 41.4 mm |
| October | 1.4 °C | 16.4 °C | 36.58 mm |
| November | -5.9 °C | 7.9 °C | 10.41 mm |
| December | -11.8 °C | 0.7 °C | 9.14 mm |
| Annual | 1 °C | 15.1 °C | 468.63 mm |
| 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 : -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 |