Sunny Days in Washington State by Region

Washington's sunshine varies radically across the Cascade Crest — from rainforest to rain shadow.

Major City Averages (Annual Sunny Days)

The Cascade Divide

• West of Cascades: 130-160 sunny days — cloudy, drizzle, mild
• East of Cascades: 190-300 sunny days — dry, hot summers, cold winters
• Transition zone (Ellensburg, Wenatchee): 180-220

Seasonal Pattern

• Summer (Jul-Sep): Statewide sun — even Seattle 25+ sunny days/month
• Winter (Nov-Feb): West = gloom (2-4 sun days/mo); East = sunny but cold
• Spring/Fall: Variable; "Juneuary" (cool, cloudy June) common west

What "Sunny Day" Means

• NWS definition: <30% cloud cover daylight hours
• "Partly cloudy" (30-70%) not counted
• Seattle has ~200+ "partly cloudy" days — feels sunnier than stat

Practical Implication

If you want sun: live east of the mountains (Yakima, Tri-Cities, Spokane, Wenatchee). If you accept gray for mild temps and greenery: west side. The divide is sharp — 50 miles can mean 150 more sunny days.