Bristol, South Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.6 °C (low) to 11.6 °C (high). Annual precipitation averages 605 Millimeters. Bristol 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 | -16.3 °C | -6.3 °C | 17.78 mm |
| February | -14.2 °C | -3.6 °C | 15.24 mm |
| March | -7.6 °C | 3.2 °C | 27.69 mm |
| April | -0.2 °C | 11.8 °C | 53.34 mm |
| May | 7.2 °C | 19.1 °C | 77.72 mm |
| June | 13.3 °C | 24.4 °C | 96.77 mm |
| July | 15.9 °C | 27.2 °C | 91.95 mm |
| August | 14.8 °C | 26.4 °C | 64.26 mm |
| September | 9.9 °C | 22 °C | 64.01 mm |
| October | 2.2 °C | 13.6 °C | 57.4 mm |
| November | -5.6 °C | 4.2 °C | 20.83 mm |
| December | -12.3 °C | -3.3 °C | 18.03 mm |
| Annual | 0.6 °C | 11.6 °C | 605.02 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 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |