The National Weather Service has a Heat Potential Beginning July 2nd
A period of warmer temperatures is expected July 2-6, with the hottest temperatures expected July 4-5. The most likely outcome is inland high temperatures peaking in the lower to mid 90s. Temperatures may begin trending cooler July 6th
Exact high temperatures are highly uncertain after the 4th of July as a good deal of model spread is still evident. The warmest model solutions are showing high temperatures in the upper 90s to around 100 degrees over inland valleys, including the Portland/Vancouver metro (15-35% chance this outcome occurs). The coolest model solutions show high temperatures in the lower to mid 80s (10% chance of occurring).
The potential for warm temperatures continues through next weekend with a 50% chance of 90 degree temperatures each day through at least Saturday July 8th. A slight risk (20%) of excessive heat continues through July 9th as well.