A significant difference between Eastern Washington and the western half of the state is its climate. While the west half of the state is located in a rainy oceanic climate, the eastern half receives little rainfall due to the rainshadow created by the Cascade Mountains. Also, due to being farther from the sea, the east side has both hotter summers and colder winters than the west. Most communities in Eastern Washington, for example, have significant yearly snowfall, while in the west snowfall is minimal and not seen every year. The east and west do still have some climatic traits in common, though: more rainfall in winter than summer, a lack of severe storms, and milder temperature ranges than more inland locations.
There is some variation in both temperature and rainfall throughout Eastern Washington. Generally, lower elevations are both hotter and drier than higher elevations. This is easily seen in the comparison between low-elevation Richland with higher elevation Spokane.
Climate data for Tri-Cities, Washington (combined average of 3 cities)
Compared to Western Washington, Eastern Washington has roughly twice the land area and one-fifth the population. According to the U.S. Census Bureau the population estimate as of July 2019 was 1,641,900. The population growth rate between the two is roughly the same. Of Washington's ten Congressional districts, Eastern Washington exactly encompasses two (the 4th and 5th), aside from a small portion of the 3rd in Skamania County.
There have been sporadic movements to create a 51st state out of Eastern Washington by splitting the current state down the Cascades, but proposals have rarely progressed out of the state legislature's committees. Bills in the Washington State Legislature which would have requested the United States Congress to take up the question were proposed in 1996, 1999, 2005, and 2017.[12] Proposed names for the new state have included Lincoln, Columbia, Liberty,[13] or simply Eastern Washington. Many of these proposals would include the Idaho Panhandle as part of the proposed state of Lincoln.
Eastern Washington tends to vote Republican, whereas Western Washington usually votes Democratic. However, Spokane, the proposed capital and largest city, tends to have a higher democratic vote than other Eastern Washington cities. Additionally, Whitman County votes Democratic.
