Marion, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 35.1 °F (low) to 56.6 °F (high). Annual precipitation averages 26.8 Inches. Marion 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 | 6.8 °F | 25.7 °F | 0.53 in. |
| February | 11.0 °F | 30.9 °F | 0.76 in. |
| March | 22.1 °F | 42.9 °F | 1.33 in. |
| April | 33.9 °F | 57.0 °F | 2.84 in. |
| May | 46.7 °F | 69.4 °F | 3.81 in. |
| June | 58.0 °F | 79.4 °F | 4.24 in. |
| July | 62.0 °F | 84.2 °F | 2.98 in. |
| August | 59.5 °F | 81.4 °F | 3.37 in. |
| September | 50.3 °F | 74.4 °F | 2.73 in. |
| October | 36.4 °F | 60.2 °F | 2.41 in. |
| November | 22.8 °F | 43.8 °F | 1.01 in. |
| December | 12.0 °F | 30.1 °F | 0.78 in. |
| Annual | 35.1 °F | 56.6 °F | 26.79 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 |