Arlington Heights, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.8 °C (low) to 14.9 °C (high). Annual precipitation averages 956.6 Millimeters. 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 | -9 °C | -0.6 °C | 51.05 mm |
| February | -7.4 °C | 1.6 °C | 49.53 mm |
| March | -2.3 °C | 7.7 °C | 57.4 mm |
| April | 3.4 °C | 14.4 °C | 95.25 mm |
| May | 9.4 °C | 20.7 °C | 115.32 mm |
| June | 15 °C | 26.4 °C | 112.27 mm |
| July | 17.9 °C | 28.8 °C | 93.22 mm |
| August | 17.2 °C | 27.7 °C | 102.62 mm |
| September | 12.7 °C | 23.9 °C | 82.8 mm |
| October | 6.1 °C | 16.8 °C | 81.79 mm |
| November | -0.2 °C | 8.9 °C | 60.96 mm |
| December | -5.7 °C | 2.3 °C | 54.36 mm |
| Annual | 4.8 °C | 14.9 °C | 956.57 mm |
| 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 : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |