Naples, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43 °F (low) to 64 °F (high). Annual precipitation averages 39.6 Inches. Naples is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 19.0 °F | 36.0 °F | 2.14 in. |
| February | 22.4 °F | 41.1 °F | 1.91 in. |
| March | 31.5 °F | 52.5 °F | 2.73 in. |
| April | 42.0 °F | 65.1 °F | 4.01 in. |
| May | 53.0 °F | 74.9 °F | 4.66 in. |
| June | 62.2 °F | 83.6 °F | 4.82 in. |
| July | 66.0 °F | 87.1 °F | 4.15 in. |
| August | 63.4 °F | 85.9 °F | 3.47 in. |
| September | 55.3 °F | 79.9 °F | 3.46 in. |
| October | 43.7 °F | 67.6 °F | 3.05 in. |
| November | 32.9 °F | 53.2 °F | 2.92 in. |
| December | 24.3 °F | 40.9 °F | 2.29 in. |
| Annual | 43 °F | 64 °F | 39.61 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |