Thanks Gitter for the reply!
I personally think that during the dog days of summer not only the sunfish but fishing as a whole slows down. I think the fish become lazy and find cover to lay under to beat the sun. Fish also find a little deeper water. Docks,bridges,brush piles,and tree overhangs in water 10 to 15 feet are usually pretty good places this time of year to find sunnies. Shallow rivers and creeks are a different story. Brush piles and deeper pockets of water are the places to look there.
Side Note: Very early morning and night fishing are the best times to fish during the HOT summer months.