Arid Climate

Have you noticed since exiting the tunnel that we see less vegetation and fewer trees? Notice the Ponderosa pines here that we did not see on the western slopes of the Cascades - yellow to orange-red bark in broad plates with black crevices. Since we left Puget Sound, we have been traveling east from a marine climate toward a true desert climate. This change takes place in a straight-line distance of about 100 miles. The Greater Seattle Metropolitan area averages about 40 inches of precipitation per year. But here on the eastern side of the Cascade Mountains, the average is a mere eight inches or less.

In Eastern Washington, the Cascade Range significantly shapes the climate, creating distinct weather patterns. Shielding the region from rain, the Cascades accumulate substantial snowfall, fostering a haven for winter sports enthusiasts. Cities like Wenatchee, Ellensburg, and the Tri-Cities bask in abundant sunshine, with up to 300 sunny days annually due to the rain shadow effect. Annual rainfall is minimal compared to Western Washington, ranging from 7 to 9 inches in central areas and increasing slightly toward Spokane, averaging 15 to 30 inches yearly. The region experiences stark temperature contrasts, with scorching summers reaching the upper 80's to mid-90's Fahrenheit and chilly winters dipping to below freezing. Geographically, Central Washington transitions from almost plains-like terrain to rolling hills towards the east, nourished by rich volcanic soil conducive to agriculture. Over 300 crops thrive here, supported by the Columbia Gorge's breathtaking landscape and the hydroelectric dams along the Columbia River, providing renewable energy and water resources for businesses and farms across the state.

Washington State Department of Commerce. (2024, January 22). The amazingly diverse climate and geography of Washington State. Washington State - Where the Next Big Thing Begins. https://choosewashingtonstate.com/research-resources/about-washington/climate-geography/