Armour, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 2.5 °C (low) to 15.5 °C (high). Annual precipitation averages 660.7 Millimeters. Armour 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 | -12.3 °C | -1 °C | 16 mm |
| February | -10 °C | 1.9 °C | 19.56 mm |
| March | -4.6 °C | 8.4 °C | 33.02 mm |
| April | 1.6 °C | 15.3 °C | 76.2 mm |
| May | 8.3 °C | 21.8 °C | 95.25 mm |
| June | 14.4 °C | 27.4 °C | 98.04 mm |
| July | 17.2 °C | 30.9 °C | 78.74 mm |
| August | 15.9 °C | 29.7 °C | 76.2 mm |
| September | 10.6 °C | 25.4 °C | 70.36 mm |
| October | 3.1 °C | 17 °C | 55.12 mm |
| November | -4.2 °C | 8.3 °C | 23.62 mm |
| December | -9.8 °C | 0.9 °C | 18.54 mm |
| Annual | 2.5 °C | 15.5 °C | 660.65 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 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |