I finally made my first 50mpg tank with normal driving (not all freeway)!

So I was hoping I would be able to do it again, but it got pretty hot in southern California this weekend (I can usually stand it, but my girlfriend needs the AC). Not only can I not hit the 50 mpg mark, but I'm struggling just to maintain 44 mpg. I set the climate control to Auto at 70. My best tank before the last one was about 48 mpg, so a loss of 4 mpg isn't bad to stay cool, but is it possible to keep up the FE when the temperature gets hot?!?

Thanks