Elmhurst, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.3 °F (low) to 59.3 °F (high). Annual precipitation averages 39.2 Inches. Elmhurst is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 16.6 °F | 31.4 °F | 2.14 in. |
| February | 19.2 °F | 35.3 °F | 2.15 in. |
| March | 28.6 °F | 46.5 °F | 2.3 in. |
| April | 38.9 °F | 58.7 °F | 3.89 in. |
| May | 49.8 °F | 70.0 °F | 4.72 in. |
| June | 59.8 °F | 80.0 °F | 4.49 in. |
| July | 65.0 °F | 84.3 °F | 3.73 in. |
| August | 63.6 °F | 82.4 °F | 4.15 in. |
| September | 55.6 °F | 75.7 °F | 3.37 in. |
| October | 43.4 °F | 62.7 °F | 3.44 in. |
| November | 32.1 °F | 48.5 °F | 2.58 in. |
| December | 22.4 °F | 36.6 °F | 2.28 in. |
| Annual | 41.3 °F | 59.3 °F | 39.24 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 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 | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |