Lomax, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42.6 °F (low) to 61.7 °F (high). Annual precipitation averages 39.5 Inches. Lomax 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 16.6 °F | 33.0 °F | 1.68 in. |
| February | 20.4 °F | 37.6 °F | 1.91 in. |
| March | 30.7 °F | 49.8 °F | 2.54 in. |
| April | 41.6 °F | 62.6 °F | 3.88 in. |
| May | 53.3 °F | 73.0 °F | 5.26 in. |
| June | 63.0 °F | 82.2 °F | 4.9 in. |
| July | 66.5 °F | 85.7 °F | 4.13 in. |
| August | 64.3 °F | 84.2 °F | 3.79 in. |
| September | 55.9 °F | 78.0 °F | 3.78 in. |
| October | 44.1 °F | 65.3 °F | 3.11 in. |
| November | 32.5 °F | 50.5 °F | 2.58 in. |
| December | 22.6 °F | 38.1 °F | 1.97 in. |
| Annual | 42.6 °F | 61.7 °F | 39.53 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| 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 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |