And with today's 90F high, PDX airport no longer has a virgin date during the month of June in that regard. Unsurprisingly 13 of June's record highs, all now in the 90s, have been set since 2016

I think the strong budding Niño has something to do with it. Getting an early start on the STJ bolsters the cross polar gradient into early summer, locking away colder air within the poles a smidge more effectively, just enough to allow for fat polar lobes to continue on spinning into the solstice

Just dumb luck mostly. They did hit 97 on 6/11/2019 and 98 on 6/12, so those stars almost aligned. Today's record was definitely low hanging fruit for them, but they should be able to easily break tomorrow's 95 as well.

I'm surprised the last decade hadn't nabbed a 90-meal yet for today's date

Something tells me this next winter is going to be brutally warmer than normal up there