Jacksonville, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.5 °C (low) to 15.2 °C (high). Annual precipitation averages 871.2 Millimeters. Jacksonville is located in USDA Plant Hardiness Zone 5b. 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 | -11.6 °C | -1.5 °C | 20.83 mm |
| February | -9.3 °C | 1.2 °C | 26.92 mm |
| March | -3.3 °C | 8.6 °C | 47.75 mm |
| April | 2.8 °C | 16.1 °C | 90.42 mm |
| May | 9.7 °C | 21.9 °C | 127.76 mm |
| June | 15.5 °C | 27.2 °C | 126.24 mm |
| July | 17.6 °C | 28.9 °C | 97.79 mm |
| August | 16 °C | 27.9 °C | 105.41 mm |
| September | 10.9 °C | 24.6 °C | 87.63 mm |
| October | 4.3 °C | 17.7 °C | 69.09 mm |
| November | -2.7 °C | 8.4 °C | 38.61 mm |
| December | -8.2 °C | 1.3 °C | 32.77 mm |
| Annual | 3.5 °C | 15.2 °C | 871.22 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 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |