Arlington Heights, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.6 °C (low) to 15.3 °C (high). Annual precipitation averages 1257.1 Millimeters. Arlington Heights is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 0.7 °C | 7.4 °C | 157.23 mm |
| February | 0.7 °C | 9.1 °C | 115.57 mm |
| March | 2.1 °C | 11.3 °C | 137.92 mm |
| April | 4.4 °C | 14.6 °C | 106.17 mm |
| May | 7.5 °C | 18.2 °C | 80.01 mm |
| June | 9.8 °C | 20.3 °C | 65.28 mm |
| July | 11.7 °C | 23.9 °C | 29.97 mm |
| August | 11.8 °C | 24.4 °C | 31.5 mm |
| September | 9.3 °C | 21.4 °C | 64.52 mm |
| October | 5.7 °C | 15.4 °C | 134.87 mm |
| November | 2.6 °C | 10.1 °C | 169.42 mm |
| December | 0.6 °C | 6.9 °C | 164.59 mm |
| Annual | 5.6 °C | 15.3 °C | 1257.05 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |