Those of you who live half a world away, save this info for your hot time of year. If you live were August is almost autumn and it is already getting cool, you better get out and go fishing - you don't have time to read this.
One of the ways to beat the heat and catch fish is to try at night. Night fishing can be good year round but it is especially attractive to me when the heat makes it miserable during the day. Bass, crappie, stripers, hybrids and catfish all feed at night here in Georgia. I know big trout feed at night but I'm not sure about walleye and other fish. No matter where you live, you can catch fish at night, though.
A favorite method of mine has been to find a bridge, tie a boat up under it, hang a light over the side, bait up several rods with minnows, sit back and watch them. It is cool, relaxing and you often catch lots of fish. The light draws minnows and shad which draw the gamefish. This is especially effective for the fish that run up rivers to spawn and then move back down as the water gets hot. Stripers, hybrids and white bass crowd up under bridges and provide lots of action.
Crappie also feed at night. They tend to live around the bridge pilings anyway, so a light drawing minnows at night is like a neon light advertising a steak house to a hungry traveler. And there's not much better than a mess of fried crappie to anybody who's hungry.
For any of the fish feeding on minnows, try to fish at different depths until you start catching them. A good depth finder helps but you can put out several rods at different depths and then move them all to the depth you start catching fish. Another trick is to try different size baits. If the crappie and stripers are feeding on young-of-the-year shad that are 1/2 inch long, they aren't likely to eat a three inch shiner minnow. Try to match the hatch. Look at the minnows in the water and either catch them for bait or use bought bait their size.
If the water is clear, try light line. Even if you lose some fish because your line is too light, it is better to hook several an lose some than to not hook any. If you use line too heavy, you may not get a bite.
Casting for bass at night is also productive. I like to cast a crankbait or spinnerbait if there is light from the moon, a shore light or from the boat. A white plug swimming along will reflect all the available light just like a baitfish. A spinnerbait with silver blades and a white skirt will do the same and the vibration of the blades will draw the fish to it. A rattle in the crankbait often helps it do the same.
If it is a dark night, I like to fish a black plastic worm on the bottom. I put two beads between the hook and the lead on a Texas rigged worm to make clicking sounds as it is fished along the bottom. I think the fish mistake that outfit for a crayfish feeding along. I don't' know how the find a black worm on the bottom at night, but they do.