Roswell, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 34.9 °F (low) to 56.8 °F (high). Annual precipitation averages 24.5 Inches. Roswell is located in USDA Plant Hardiness Zone 5a. 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 | 6.7 °F | 25.4 °F | 0.51 in. |
| February | 10.9 °F | 30.8 °F | 0.67 in. |
| March | 21.8 °F | 43.0 °F | 1.19 in. |
| April | 33.7 °F | 57.5 °F | 2.73 in. |
| May | 46.3 °F | 69.4 °F | 3.6 in. |
| June | 57.4 °F | 79.4 °F | 3.78 in. |
| July | 61.5 °F | 84.8 °F | 2.87 in. |
| August | 59.3 °F | 82.6 °F | 2.82 in. |
| September | 50.5 °F | 74.9 °F | 2.78 in. |
| October | 36.5 °F | 60.5 °F | 2.13 in. |
| November | 22.9 °F | 43.7 °F | 0.88 in. |
| December | 11.6 °F | 30.0 °F | 0.58 in. |
| Annual | 34.9 °F | 56.8 °F | 24.54 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |