Curran, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43 °F (low) to 63.2 °F (high). Annual precipitation averages 38.9 Inches. Curran is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 18.8 °F | 35.3 °F | 2.12 in. |
| February | 22.2 °F | 40.3 °F | 1.92 in. |
| March | 31.4 °F | 51.8 °F | 2.74 in. |
| April | 42.0 °F | 64.5 °F | 4.06 in. |
| May | 53.5 °F | 74.4 °F | 4.68 in. |
| June | 62.6 °F | 82.9 °F | 4.62 in. |
| July | 65.7 °F | 85.9 °F | 3.7 in. |
| August | 63.5 °F | 84.6 °F | 3.28 in. |
| September | 55.3 °F | 79.5 °F | 3.39 in. |
| October | 43.8 °F | 67.0 °F | 3.1 in. |
| November | 33.1 °F | 52.3 °F | 3.0 in. |
| December | 24.2 °F | 40.4 °F | 2.26 in. |
| Annual | 43 °F | 63.2 °F | 38.87 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 |