Arlington Heights, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.6 °F (low) to 58.8 °F (high). Annual precipitation averages 37.7 Inches. Arlington Heights 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 15.8 °F | 30.9 °F | 2.01 in. |
| February | 18.6 °F | 34.9 °F | 1.95 in. |
| March | 27.9 °F | 45.9 °F | 2.26 in. |
| April | 38.1 °F | 57.9 °F | 3.75 in. |
| May | 49.0 °F | 69.3 °F | 4.54 in. |
| June | 59.0 °F | 79.5 °F | 4.42 in. |
| July | 64.3 °F | 83.9 °F | 3.67 in. |
| August | 62.9 °F | 81.9 °F | 4.04 in. |
| September | 54.8 °F | 75.1 °F | 3.26 in. |
| October | 42.9 °F | 62.2 °F | 3.22 in. |
| November | 31.6 °F | 48.0 °F | 2.4 in. |
| December | 21.8 °F | 36.2 °F | 2.14 in. |
| Annual | 40.6 °F | 58.8 °F | 37.66 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |