There was lightning and thunder (and hail depending on where you were) in the last year and even big summer across the sky lightning events like this in the last 5-7 [actually 8]years (I was on an airplane landing at SFO for it). It's just not common, and 100+ temperatures aren't common so together it's pretty weird. If it was the US central plains, it would be Tuesday during every summer month.

[Edit It was 2012:]

https://www.sfchronicle.com/bayarea/article/Thunder-lightnin...