Last year the 97 on June 30th was the hottest of the summer. The average over the past 10 years is July 28th, and you can see in about half the years the hottest of summer is in late July or August.
Cool marine air is surging inland nicely at 11pm with temperatures in most of the Willamette Valley down to around 70. That cool air will continue to pour in through tomorrow. High temps should be 15-20 degrees cooler as a result. Part of the cooling will come from extensive mid-level clouds the first part of tomorrow due to an upper-level disturbance moving by.
Ahead of that disturbance this evening there is quite a bit of thunderstorm action moving north along the east slopes of the southern Oregon Cascades…actually heading into the Central Cascades at this hour. So I wouldn’t be surprised to see flashing to our southeast within a couple of hours.
Chief Meteorologist Mark Nelsen