Wheaton, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.1 °F (low) to 59.5 °F (high). Annual precipitation averages 39.5 Inches. Wheaton is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 15.5 °F | 31.0 °F | 2.11 in. |
| February | 18.1 °F | 35.0 °F | 2.05 in. |
| March | 27.6 °F | 46.7 °F | 2.34 in. |
| April | 38.0 °F | 59.5 °F | 3.89 in. |
| May | 49.0 °F | 70.9 °F | 4.89 in. |
| June | 59.0 °F | 80.6 °F | 4.55 in. |
| July | 63.8 °F | 84.6 °F | 3.78 in. |
| August | 62.2 °F | 82.5 °F | 4.14 in. |
| September | 54.2 °F | 76.1 °F | 3.35 in. |
| October | 42.0 °F | 62.9 °F | 3.51 in. |
| November | 31.0 °F | 48.3 °F | 2.59 in. |
| December | 21.2 °F | 36.2 °F | 2.25 in. |
| Annual | 40.1 °F | 59.5 °F | 39.45 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°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 |