Ipswich, South Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.1 °C (low) to 12.4 °C (high). Annual precipitation averages 525.8 Millimeters. Ipswich 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 Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -16.1 °C | -5.6 °C | 9.91 mm |
| February | -13.9 °C | -2.8 °C | 13.97 mm |
| March | -7.4 °C | 4.2 °C | 22.35 mm |
| April | -0.6 °C | 12.9 °C | 45.47 mm |
| May | 6.6 °C | 19.9 °C | 78.49 mm |
| June | 12.7 °C | 25.3 °C | 89.92 mm |
| July | 15.3 °C | 28.3 °C | 83.06 mm |
| August | 13.8 °C | 27.4 °C | 60.45 mm |
| September | 8.5 °C | 22.8 °C | 52.07 mm |
| October | 1.1 °C | 14.3 °C | 42.42 mm |
| November | -6.6 °C | 5 °C | 14.48 mm |
| December | -12.6 °C | -2.7 °C | 13.21 mm |
| Annual | 0.1 °C | 12.4 °C | 525.8 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| 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 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |