What is the average lake temperature in western Washington in July?
Lake temperatures vary with altitude and depth. Shallow lakes at lower elevations tend to be warmer. A buoy in Lake Washington on the first day of July reported 68, while one in Lake Sammamish reported 69. These buoys are in the middle of the lakes, so expect warmer temperatures near shore. Black Lake in Thurston county is in the low 70's, while Blackmans Lake in Snohomish county is near 70. Expect several degrees warming by the end of the month, depending upon the weather we experience.