Jacksonville, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 38.3 °F (low) to 59.3 °F (high). Annual precipitation averages 34.3 Inches. 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 | 11.2 °F | 29.3 °F | 0.82 in. |
| February | 15.3 °F | 34.1 °F | 1.06 in. |
| March | 26.1 °F | 47.5 °F | 1.88 in. |
| April | 37.0 °F | 60.9 °F | 3.56 in. |
| May | 49.5 °F | 71.4 °F | 5.03 in. |
| June | 59.9 °F | 81.0 °F | 4.97 in. |
| July | 63.6 °F | 84.1 °F | 3.85 in. |
| August | 60.8 °F | 82.2 °F | 4.15 in. |
| September | 51.7 °F | 76.2 °F | 3.45 in. |
| October | 39.8 °F | 63.8 °F | 2.72 in. |
| November | 27.1 °F | 47.2 °F | 1.52 in. |
| December | 17.2 °F | 34.4 °F | 1.29 in. |
| Annual | 38.3 °F | 59.3 °F | 34.3 in. |
| 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 : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |