Reliance, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 34.8 °F (low) to 59.5 °F (high). Annual precipitation averages 22.1 Inches. Reliance 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 | 8.6 °F | 30.0 °F | 0.49 in. |
| February | 12.3 °F | 34.6 °F | 0.62 in. |
| March | 22.1 °F | 46.5 °F | 0.99 in. |
| April | 32.8 °F | 58.9 °F | 2.45 in. |
| May | 44.9 °F | 69.8 °F | 3.4 in. |
| June | 55.9 °F | 80.2 °F | 3.77 in. |
| July | 61.3 °F | 87.9 °F | 2.73 in. |
| August | 59.1 °F | 86.0 °F | 2.51 in. |
| September | 49.6 °F | 78.0 °F | 2.1 in. |
| October | 35.7 °F | 62.4 °F | 1.8 in. |
| November | 22.6 °F | 46.3 °F | 0.7 in. |
| December | 12.7 °F | 33.6 °F | 0.55 in. |
| Annual | 34.8 °F | 59.5 °F | 22.11 in. |
| 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 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |