Dallas, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 36.1 °F (low) to 59.9 °F (high). Annual precipitation averages 25.9 Inches. Dallas 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 | 11.7 °F | 33.0 °F | 0.49 in. |
| February | 14.9 °F | 37.3 °F | 0.72 in. |
| March | 23.7 °F | 47.7 °F | 1.21 in. |
| April | 33.9 °F | 57.9 °F | 2.88 in. |
| May | 45.3 °F | 69.2 °F | 4.04 in. |
| June | 56.2 °F | 79.8 °F | 4.34 in. |
| July | 61.8 °F | 87.1 °F | 2.92 in. |
| August | 59.6 °F | 85.0 °F | 3.15 in. |
| September | 50.3 °F | 76.9 °F | 2.5 in. |
| October | 36.6 °F | 62.2 °F | 2.23 in. |
| November | 24.3 °F | 47.2 °F | 0.74 in. |
| December | 15.1 °F | 35.4 °F | 0.65 in. |
| Annual | 36.1 °F | 59.9 °F | 25.87 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 5a : -20°F to -15°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |