Forestburg, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 1.8 °C (low) to 14.6 °C (high). Annual precipitation averages 612.7 Millimeters. Forestburg 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 | -13.8 °C | -2.9 °C | 13.21 mm |
| February | -11.6 °C | 0.3 °C | 15.49 mm |
| March | -5.4 °C | 6.9 °C | 27.69 mm |
| April | 1 °C | 15.2 °C | 72.39 mm |
| May | 8.1 °C | 21.6 °C | 87.88 mm |
| June | 14.2 °C | 27.1 °C | 98.04 mm |
| July | 16.5 °C | 30 °C | 73.41 mm |
| August | 15.3 °C | 29.1 °C | 74.68 mm |
| September | 10.2 °C | 24.7 °C | 61.98 mm |
| October | 2.4 °C | 16.6 °C | 52.07 mm |
| November | -4.8 °C | 7.3 °C | 21.59 mm |
| December | -11.1 °C | -0.4 °C | 14.22 mm |
| Annual | 1.8 °C | 14.6 °C | 612.65 mm |
| 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 : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |