In AZ, it's riding by 5:30 and in no later than 8:30-9:00 (as AZ Fiddle says.) Sure, it's a dry heat. Just like hell.

I wear a Camelback & make sure it's filled with ice water. It encourages small sips during the ride & keeps me cooler.

It's a good time to hit a spinning class or do weight training - or both.