Spencer, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 1.8 °C (low) to 14 °C (high). Annual precipitation averages 668.8 Millimeters. Spencer 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 | -13.8 °C | -3.4 °C | 13.46 mm |
| February | -11.4 °C | -0.4 °C | 19.3 mm |
| March | -5.4 °C | 6.2 °C | 31.5 mm |
| April | 1.1 °C | 14.2 °C | 74.17 mm |
| May | 8.2 °C | 20.9 °C | 95 mm |
| June | 14.4 °C | 26.6 °C | 101.35 mm |
| July | 16.7 °C | 29.4 °C | 81.53 mm |
| August | 15.3 °C | 28.1 °C | 78.74 mm |
| September | 10.3 °C | 24.1 °C | 75.44 mm |
| October | 2.6 °C | 16.1 °C | 56.64 mm |
| November | -5 °C | 6.7 °C | 24.13 mm |
| December | -11.1 °C | -0.9 °C | 17.53 mm |
| Annual | 1.8 °C | 14 °C | 668.79 mm |
| 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 : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |