Roxana, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 46.9 °F (low) to 65.5 °F (high). Annual precipitation averages 43.7 Inches. Roxana is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 23.1 °F | 39.2 °F | 2.62 in. |
| February | 26.7 °F | 44.6 °F | 2.38 in. |
| March | 35.4 °F | 54.8 °F | 3.4 in. |
| April | 46.2 °F | 66.2 °F | 4.82 in. |
| May | 56.9 °F | 75.5 °F | 5.23 in. |
| June | 65.9 °F | 84.3 °F | 4.49 in. |
| July | 69.7 °F | 87.6 °F | 4.2 in. |
| August | 67.7 °F | 86.5 °F | 3.79 in. |
| September | 59.4 °F | 80.3 °F | 3.22 in. |
| October | 47.6 °F | 68.6 °F | 3.33 in. |
| November | 36.6 °F | 54.9 °F | 3.53 in. |
| December | 27.8 °F | 43.9 °F | 2.68 in. |
| Annual | 46.9 °F | 65.5 °F | 43.69 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |