Brocton, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42.9 °F (low) to 62.8 °F (high). Annual precipitation averages 40.9 Inches. Brocton 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 | 19.1 °F | 35.0 °F | 2.51 in. |
| February | 22.2 °F | 39.6 °F | 2.1 in. |
| March | 31.4 °F | 51.2 °F | 2.88 in. |
| April | 42.1 °F | 64.0 °F | 4.45 in. |
| May | 53.3 °F | 74.3 °F | 4.38 in. |
| June | 62.4 °F | 82.7 °F | 4.76 in. |
| July | 65.1 °F | 85.3 °F | 4.09 in. |
| August | 62.8 °F | 84.1 °F | 3.08 in. |
| September | 55.3 °F | 79.1 °F | 3.04 in. |
| October | 43.8 °F | 66.7 °F | 3.55 in. |
| November | 33.1 °F | 52.0 °F | 3.45 in. |
| December | 24.7 °F | 39.8 °F | 2.57 in. |
| Annual | 42.9 °F | 62.8 °F | 40.86 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 |