Garden City, South Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.3 °C (low) to 11.5 °C (high). Annual precipitation averages 613.2 Millimeters. Garden City is located in USDA Plant Hardiness Zone 4b. 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 | -16.2 °C | -6.3 °C | 14.99 mm |
| February | -14.2 °C | -3.6 °C | 16.51 mm |
| March | -7.6 °C | 3.3 °C | 25.4 mm |
| April | -0.4 °C | 11.7 °C | 56.39 mm |
| May | 6.8 °C | 18.8 °C | 81.03 mm |
| June | 12.8 °C | 24.3 °C | 102.62 mm |
| July | 15.5 °C | 27.1 °C | 90.17 mm |
| August | 14.2 °C | 26.2 °C | 66.8 mm |
| September | 9.3 °C | 21.8 °C | 64.26 mm |
| October | 1.6 °C | 13.4 °C | 57.4 mm |
| November | -5.9 °C | 4.4 °C | 20.57 mm |
| December | -12.3 °C | -3.2 °C | 17.02 mm |
| Annual | 0.3 °C | 11.5 °C | 613.16 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 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |