With some good advice and a lot of time well spent on the bank over the years testing different areas, depths and baits we've found that there is a somewhat reliable pattern to chasing Summertime blues, IMHO. Not wanting to give up on catfishing because the Summer heat sets in and that the bite becomes more hit and miss has resulted in quite few enjoyable fishing trips over the Summers and thought I might share what's worked for me, all just in my opinion.
Typically fish at night with the normally cooler temperatures to avoid the heat/UV and find that the bite is definitely better at this time of year after dark. The depth normally targeted is from 18 ft - 3ft but I prefer 12ft to 6ft because I think there is a better chance of finding fish moving through at this depth. Have found that they usually move though in waves and don't stay put in any one area very long it seems. Typically fish Lavon, sometimes Hubbard but deeper waters would probably work on deeper lakes I would think but the main concern would be to fish above the thermocline for me here, when a thermocline exists. Fishing flats/coves/points in areas with submerged timber,creek channels, levees and other structure has proven well along with areas with ledges and drop offs. Tend to do better with tough baits like large gizzard shad, perch ,blue gills, carp and drum that don't get knocked off the hook easily by turtles and gar. Threadfin hooker shad usually results in a lot of re-baiting. Late evening, night and early in the mornings have been the most productive times usually and wind plays a large part in helping the bite. Windier the better but low winds have occasionally worked.
At any rate, thought I would share what has seemed to work best for me fishing for blues in the Summer and hope that any of this can help on other lakes as well. Here are a few pictures of some the better fish for me so far this Summer:

Great post Dave

Awesome fish. Good job.

Nice Fish.

Thanks all. Think I'm gonna be ready to see the daytime highs about 50 degrees colder soon

Toads.

Nice Fish. Good job.

Hit the bank lastnight with one of my fishing buddies and the results were good with the South winds. We fished a flat in 6-7ft with submerged timber using cut blue gills for bait. Finished the night with a 14,24,28,30,32,35,38 and Lou topped it off with a heck of a nice Summertime 50lbr! Good times!

The 50lbr :


The 30's:

Best post on the TFF in along time!WTG Dave and Lou!

Wow those are some pigs. nice work.

Summertime beast! Congrats! Looks like a heck of a trip!

Great trip for y'all last night as well 2fish! I'm
hoping to try and get my nephews on a few fish like those y'all banked
last night. Great work out there!

great post, thanks for sharing and those are some great fish, well done sir!

Awesome work Dave! U da man!

WOW