Washington, Kansas has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42 °F (low) to 64.8 °F (high). Annual precipitation averages 31.9 Inches. Washington 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 | 17.0 °F | 37.5 °F | 0.76 in. |
| February | 20.6 °F | 42.2 °F | 1.07 in. |
| March | 30.5 °F | 54.2 °F | 1.85 in. |
| April | 40.5 °F | 64.9 °F | 2.98 in. |
| May | 52.1 °F | 74.9 °F | 4.67 in. |
| June | 62.5 °F | 84.8 °F | 4.66 in. |
| July | 67.0 °F | 89.6 °F | 4.38 in. |
| August | 64.7 °F | 87.6 °F | 3.59 in. |
| September | 55.3 °F | 80.4 °F | 3.06 in. |
| October | 42.7 °F | 68.1 °F | 2.37 in. |
| November | 30.3 °F | 52.9 °F | 1.44 in. |
| December | 20.9 °F | 40.9 °F | 1.09 in. |
| Annual | 42 °F | 64.8 °F | 31.92 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 6a : -10°F to -5°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 |