Burnham, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.1 °F (low) to 59.6 °F (high). Annual precipitation averages 39.7 Inches. Burnham 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 | 18.9 °F | 32.8 °F | 2.27 in. |
| February | 21.5 °F | 36.4 °F | 2.1 in. |
| March | 30.4 °F | 46.4 °F | 2.37 in. |
| April | 40.4 °F | 58.6 °F | 3.66 in. |
| May | 51.0 °F | 69.4 °F | 4.24 in. |
| June | 61.0 °F | 79.3 °F | 4.55 in. |
| July | 66.5 °F | 83.2 °F | 4.35 in. |
| August | 65.1 °F | 81.8 °F | 4.12 in. |
| September | 57.4 °F | 76.0 °F | 3.26 in. |
| October | 45.6 °F | 63.3 °F | 3.63 in. |
| November | 34.5 °F | 49.6 °F | 2.8 in. |
| December | 24.5 °F | 37.9 °F | 2.33 in. |
| Annual | 43.1 °F | 59.6 °F | 39.68 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 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |