When I lived in eastern Washington for summer shooting I was done my 9amOne thing that torques me is the two ranges I have access to, no shooting til 9;00AM, only get maybe an hour to1-1/2hrs before the sun hits hard and mirage goes nuts, then start sweating walking out to targets. I still stay out til noon, but, I do ask myself why I do it at times, mostly just to practice in the conditions is what I keep telling myself. I can never accuse it of being dull.
Thankfully the private areas and local gun club had no hours, show up and open gate.
By noon mirage was normally so thick it was silly to try and hit anything in it at any fun distances.
Can only imagine mixing it with some humidity.