Carson, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.1 °C (low) to 16 °C (high). Annual precipitation averages 885.7 Millimeters. Carson is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11 °C | -0.4 °C | 20.83 mm |
| February | -8.7 °C | 2.3 °C | 26.67 mm |
| March | -2.6 °C | 9.7 °C | 47.75 mm |
| April | 3.4 °C | 16.7 °C | 91.19 mm |
| May | 10.3 °C | 22.4 °C | 137.16 mm |
| June | 16.2 °C | 27.8 °C | 133.86 mm |
| July | 18.3 °C | 29.8 °C | 96.52 mm |
| August | 16.8 °C | 28.7 °C | 99.06 mm |
| September | 11.6 °C | 25.3 °C | 85.85 mm |
| October | 4.7 °C | 18.1 °C | 72.9 mm |
| November | -2.4 °C | 9.3 °C | 40.89 mm |
| December | -7.9 °C | 2.2 °C | 33.02 mm |
| Annual | 4.1 °C | 16 °C | 885.7 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |