Valley weather has been a little bizarre over the past week or so. Last Friday, Phoenix officially hit 100 degrees for the first time in 2015. Then on Sunday night, we had rain — which is pretty rare for May — and temperatures early Monday evening were into the lower 70s. 

So what’s going on? And does it give us any idea about what kind of summer we’ll have?

We talked with Randy Cerveny, professor of geographical science at Arizona State University. He’s also the author of “Weather’s Greatest Mysteries Solved.”