As you've probably guessed, Suncadia gets its name because of the region's fantastic sunny weather. This is caused by the proximity of mountains and the direction of the wind. Scientifically speaking, Suncadia benefits from the westerly winds rushing down the eastern slopes of the Cascade mountains. As the air descends down the mountains, the clouds evaporate which gives you sunny skies (this also explains why Suncadia has quite a bit of wind as well). You can see in the images below how there is a distinct gap in the clouds that runs parallel to the Cascade mountains.
The graphs below proves this by comparing a few Cle Elum weather stats versus Seattle weather stats. You can see that Cle Elum receives much less rain than Seattle each month, with the biggest variance occurring in the winter months when Seattle is getting hammered with rain.
Cle Elum receives around 250 sunny days each year compared to around 150 for Seattle (I'm actually surprised that Seattle gets 150 sunny days a year).
The second graph shows the average high temperature of Cle Elum versus Seattle. Interestingly, with the exception of the winter months, the average high temperature is relatively the same.
So, in a nutshell, Cle Elum receives a lot more sun, less rain and is roughly the same temperature as Seattle (with the exception of the winter months).
