I use dirt holes in hot weather but will use more flat sets simply for the reason that it's hot and less stress than digging a hole.

Here's an idea to try. I use a 2" auger bit on a cordless drill to make my dirt holes but sometimes I just want less. Find something you want to use as a backer like a flat set, a clump of sage grass, a rock or log end. Instead of just smearing lure on the backer I'll use my anchor driver, either a piece of rebar or a 1/2" piece of coal roll and make a small hole either in my backer or right at the base.

My theory with this set is if a coyote, coon, cat or whatever critter can investigate my set and instantly find the lure or bait and that curiosity is satisfied then they aren't moving around searching. If I can lure them to my set and keep their curiosity by having my lure/bait hidden that keeps feet moving and more likely to find my trap pan.

My favorite hot weather set is the compass set. Quick, easy, no backer, works anywhere you can bed a trap, can be totally hidden from set shy critters and offers 4 options to induce curiosity. No bait means less ants and no backer means I can make the set anywhere without disturbing the natural settings!