I live in the Tri-Cities. Pasco, Kennewick, Richland. Yes we get temps in this range sometime during the summer, but it hasn’t gotten up to 115 degrees in many years. What IS unusual about this is it has NEVER lasted this long. Usually a nine day spell at the most then it cools down. This is going on way beyond that.
It’s also a bit early for this kind of heat. It usually arrives mid-July through mid-August.