I find getting up at the crack of dawn to ride during the hot months is better than late evening rides. The pavement is cool and it's nice to ride with a beautiful sunrise. When you ride during the day, consider adding at least 2-5 degrees more to the temps from the heat radiating off the road.

I love to ride at night in the winter months but in the summer months I end up getting pinged by june bugs from the lights I run.