Roscoe, South Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.1 °C (low) to 12.1 °C (high). Annual precipitation averages 542.3 Millimeters. Roscoe 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 | -15.8 °C | -5.7 °C | 13.72 mm |
| February | -13.7 °C | -3.1 °C | 16.51 mm |
| March | -7.6 °C | 3.9 °C | 23.37 mm |
| April | -0.9 °C | 12.4 °C | 46.23 mm |
| May | 6.2 °C | 19.5 °C | 80.52 mm |
| June | 12.3 °C | 24.9 °C | 94.74 mm |
| July | 14.9 °C | 28.2 °C | 82.3 mm |
| August | 13.6 °C | 27.4 °C | 57.4 mm |
| September | 8.3 °C | 22.6 °C | 49.78 mm |
| October | 0.9 °C | 13.8 °C | 44.7 mm |
| November | -6.6 °C | 4.6 °C | 17.27 mm |
| December | -12.5 °C | -2.9 °C | 15.75 mm |
| Annual | -0.1 °C | 12.1 °C | 542.29 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | Over 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 | Dfb - Humid Continental Mild Summer, Wet All Year |