Lyons, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 34.6 °F (low) to 55.4 °F (high). Annual precipitation averages 27.1 Inches. Lyons 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 | 6.0 °F | 24.2 °F | 0.57 in. |
| February | 10.1 °F | 29.0 °F | 0.82 in. |
| March | 21.5 °F | 41.4 °F | 1.38 in. |
| April | 33.5 °F | 55.8 °F | 3.03 in. |
| May | 46.3 °F | 68.1 °F | 3.65 in. |
| June | 57.6 °F | 78.4 °F | 4.04 in. |
| July | 61.5 °F | 82.9 °F | 3.3 in. |
| August | 58.8 °F | 80.2 °F | 3.43 in. |
| September | 49.7 °F | 73.3 °F | 2.87 in. |
| October | 36.2 °F | 59.5 °F | 2.09 in. |
| November | 22.5 °F | 42.8 °F | 1.05 in. |
| December | 11.6 °F | 29.0 °F | 0.84 in. |
| Annual | 34.6 °F | 55.4 °F | 27.07 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 | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |