Chester, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 1.5 °C (low) to 12.5 °C (high). Annual precipitation averages 900.2 Millimeters. Chester 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 | -14.3 °C | -4.9 °C | 21.59 mm |
| February | -12.2 °C | -2.4 °C | 23.88 mm |
| March | -5.6 °C | 4.6 °C | 44.2 mm |
| April | 1.1 °C | 13.1 °C | 95 mm |
| May | 7.8 °C | 19.9 °C | 116.59 mm |
| June | 13.7 °C | 25.2 °C | 151.89 mm |
| July | 15.5 °C | 27.1 °C | 109.22 mm |
| August | 14.1 °C | 25.9 °C | 105.41 mm |
| September | 9.4 °C | 22.4 °C | 91.69 mm |
| October | 2.7 °C | 14.9 °C | 68.33 mm |
| November | -4 °C | 5.9 °C | 41.66 mm |
| December | -10.4 °C | -1.7 °C | 30.73 mm |
| Annual | 1.5 °C | 12.5 °C | 900.19 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 | Dfa - Humid Continental Hot Summers With Year Around Precipitation |