In the south bay area where we live, yesterday was 104. About 30 miles away on the coast, Santa cruz/Monterey bay, it was low 60’s. A 40 degree difference within 30 miles! Amazing!
We love making the turn on the 5 freeway into the San Francisco area in the summer - up the 5 corridor during that time it is often over 110 passing through Patterson and Firebaugh - dogs won’t get out of the car at the rest stop.
We hit SF and it’s 65 and blissfully foggy, pure heaven after the extreme heat. Just make sure you have a place to park your car - people from inland areas pile into SF during the weekend to get out of the extreme inland heat.