To use this source would require a little background understanding about definitions and meanings. Electricity and Natural Gas Prices by Major Utility, Energy User News EUN lists the average electricity prices by the 170 EIA surveyed utilities for industrial and commercial sectors on a rotating monthly basis. Data appear to have a 4-5 month lag. They also list the most recent monthly degree days by major city including Seattle and Portland. This is a rotating series of information that appears in Clearing Up every week.
Most data are regional which includes Washington, Oregon, and Idaho.
Typically they include monthly data for the most recent year and annual data back to 1980. Regional electricity statistics including total loads, spot market prices, and sales by sector.