I've noticed a significant drop (3 MPG) with the hot weather here in Vegas,
I'm averaging 26 MPG now in City/Suburban driving, vs 29 earlier
It's been 105 to 115 here, and all my driving is in the middle of the day when it's sunny and hot
The A/C does a great job keeping the car cool. And even when the car has been sitting in the sun for an hour or 2, the automatic climate control kicks on the Max, and cools things down really quick.
p.s. These MPG figures are based on actuals (i.e. miles traveled divided by gallons pumped in)
The dash Trip computer seems to show MPG that is 1 MPG higher than actual.