Thankfully it’s as hot as it’s going to get across most of the country. In some places, the temps are already starting to dip a bit. For the rest of us there are a few weeks of hot weather left, but it shouldn’t get any hotter. With the water temps maxed out, how do we go about catching fish?

First - what’s happening

Whole books have been written on the thermocline, but we’ll try to compile a quick crash course here in a few paragraphs to lay a foundation for today’s conversation.

Basically, the thermocline is the maximum depth in the water column at which life is able to thrive. The thermocline is pushed deeper and deeper as water temperatures rise. In addition to higher water temps, the depth of the thermocline is determined in part by the clarity of the water, which effects how far into the water sunlight can reach.

Microscopic plants known as phytoplankton (algae for example) need sunlight for photosynthesis. This photosynthesis is critical for the existence and growth of the plants, and also produces oxygen as a byproduct. Then microscopic animals known as zooplankton come in and add the next step in the food chain as they feed on the algae.

Then baitfish feed on the plankton and bass feed on the baitfish. So to sum all of that up, the thermocline is the deepest water (which is also the coolest water) that bass can find the two most critical elements for their survival, oxygen and food.

The problem

As water temps reach their peak, the thermocline pushes very deep. This is especially the case on clear water reservoirs where the sunlight can penetrate to great distances. With 30, 40 and even 50- feet of water or more overhead, the adverse effects of that amount of water pressure on the baitfish causes them to leave the depths and seek an alternative refuge and food source in shallower water.

As the bait leaves, the bass follow. And now the areas that have been productive all summer see a very scattered speckling of bass and bait still present. Meanwhile some of the fish are now shallow, and others are somewhere in between. This is where we basically are right now.

How to catch them during this shift

One of the more obvious answers to how to catch fish when it’s hot is night fishing. Unfortunately even this is getting a little tough though as fish have been pushed super deep. Most pier lights that attract fish don’t reach a depth that is cool enough to be comfortable for the bait and bass to thrive.

Even though this type of fishing isn’t as good as it was back in May and June, you can still look to it to catch fish. Focus on the deepest lights you can find and don’t be afraid to slow way down to fishing a worm.

Targeting bass in shady spots up shallow is another critical area of focus this time of year. The shade offers slightly cooler water and thus a sanctuary for the bass and a supposed refuge for the baitfish. But the peace for the bream and bluegill that frequent these locals is quickly busted up, as bass blow through and terrorize the local fare.

Looking deep in the daytime is still an option too, but don’t focus as much on the bottom of the water column. Though those brushpiles in 25- feet of water will still hold a few fish, you’ll find that a lot of the better bass are now suspended near the surface or a few feet below it, chasing schools of baitfish that have vacated the deeper water.

Topwaters are fantastic offerings in these situations, as they are able to call fish up from varying depths, while single swimbaits rigged on jigheads are another good choice.

Focusing on bait and insect spawns is another great way for things to get good in a hurry right now. Mayfly and cicada hatches concentrate bass and baitfish into small shallow areas, while spawning bream and bluegill do the same. Taking advantage of these concentrations of fish is a key way to maximize production.

In conclusion

Understanding the basics of the ecosystem that you’re fishing is critical. Finding the relative depth of the thermocline and thus essentially the bottom of the bite window, you can narrow your search for productive water. Then sampling a little of everything throughout that column of water will help you quickly identify where you need to be looking.

Somedays you’ll find that versatility is key, as you’ll catch fish at varying depths throughout a day of fishing. Other times, you’ll find a sweet spot in the water column where the majority of the bait has stalled out, and be able to catch lots of fish on a swimbait in 12- feet of water for example. The main objective is to fish loose this time of year and rely more than ever on letting the fish tell you what to do.