By Ben Leal

August in Iowa can be quickly summed up in one word…hot! July has come and gone and average temps have been hovering around the mid 80’s, August continues the trend and even throws in a few 90 degree days. By now surface water temperatures on area lakes have reached 75 – 80 degrees or more. All this adds up to one thing…finicky fish.

Anglers will venture out but most will hit the lakes early in the morning or wait for the cool of the evening and night to chase after their favorite quarry. But quality fish and even quantity can still be caught during the heat of the day. Sure…you could be home in the living room soaking up the air conditioning and watching your favorite fishing shows, but there will be this nagging question…” are the fish biting right now?”

The short answer, yes. So the question then becomes how do we successfully target these tight lipped fish…the sun beaming down and sweat rolling down your back fishing. Well, we’re going to figure that out, break it down and give you some tools to add to your fishing arsenal.

Environmental Influences
Okay, so let’s talk about some of the things that will influence where the fish are and where they are not. Like any living organism, those that inhabit lakes, rivers and streams need oxygen to survive. As water moves past their gills, microscopic bubbles of oxygen gas in the water called dissolved oxygen (DO) are transferred from the water to their blood. Warmer day’s heat up the water and DO becomes an important factor in finding the fish.

As summer wears on three layers of water develop in Iowa lakes and reservoirs. The depth of these layers will depend on the depth of the lake. The top layer is called the epilimnion and gets the most sun and is the warmest of the three. The bottom layer is called hypolimnion which is least affected by the sun and is the coldest. The middle layer is called the thermocline, a thin but distinct layer in a body of water.

The thermocline is of primary interest to fisherman due to the fact that this is where the highest levels of DO will be found. The warm water at the surface will have DO but not at comfortable concentrations for fish and the water at the bottom of the lake will be too cold and the DO levels there will be very low due to the lack of sun and the decomposition that usually occurs at those depths.

This is a key factor when it comes to chasing after these finicky fish during the summer heat. If you keep that in mind as you spend time searching for active fish, you will be more successful than most.

On top of temperature, both above and below the surface of the water is the barometric pressure. I know that most of you have experienced this…you plan a day of fishing and storms roll in and ruin your day. Forecast for the following day is clear with lots of sunshine. Rolling out early, you arrive at the lake, back down the ramp and launch your boat. It’s a beautiful morning and you just know that the fish are going to jump in the boat. An hour passes, and then two and you’ve only managed a short strike…” what’s happened to fish?” you ask yourself. Answer is…a high-pressure system that usually follows storms, especially when skies are clear and blue.

Anglers spend lots of time and money trying to figure out how to fool these feisty predators into taking their baits. Knowing that fish will likely be concentrated deeper this time of year, we need to change our strategies accordingly.

One of the best tools we have at our fingertips are lake maps that show depth and structure. This goes for any fish we’re chasing during the summer. Good electronics are very helpful as well and many of the newer models are compatible with Lakemaster and Navionics lake map chips. Take time to look for deep creek channels, especially those that have bends and points in them. Bass will concentrate in these areas and follow breaklines or channels from home areas to feeding stations.

Some bass will suspend in and around 20 feet, most bass will feed at about 10-20 foot of water and then move off to deeper water to rest. Crankbaits are great tools, searching for actively feeding fish. On depth finders, if you find the bait fish you’ll find bass. Active bass tends to be those in groups of two or three. These bass are either holding close to the edge of the drop-off or right off. They will wait and ambush prey as it swims by.

Throw a deep diving crankbait up toward the shallow and run in out to the edge of the drop-off. If you have some structure along the drop-off, like stumps and logs, you can bounce your crankbait off these and entice bass to bite, even if they’re not actively feeding. Bass see something swimming right by that appears injured they’ll strike out of a reaction…easy meal.

Jigs, creature baits and plastic worms can be very effective at these depths. These do very well when fish are relating to structure and holding tight to it. Keep your eye on your fishing line though as you move your bait through the water, more often than not the fish will pick up your bait on the drop and move off with it.

Bass are not always found in deeper cooler water during the heat of the day, you’ll also find them shallow. When the sun is shining high in the sky and your standing in your boat, sweat dripping off your brow, you’re thinking to yourself, “man some shade would be really great right about now.” Bass or no different, they will be hiding in shady spots along docks and on the shady side of trees and stumps.

I remember fishing one really hot afternoon out and away from the shoreline. As I pulled around a bend along the shoreline there was a large willow tree hovering over the water creating plenty of shade. I knew there were a couple stumps out under that shade in about 10-foot of water, so I threw my 7-inch plastic worm up close and no sooner had it hit the bottom than a nice 3-lb bass picked it up. The difference was the shade and structure, something to hold the fish and a bit cooler water.

Weed lines are also great for catching summertime fish. If you find a weed bed, look for small clumps of weeds that are off by themselves. These small irregular weedbeds, little points or indentations, and interior holes will draw most of the bass inhabiting the grass. Early in the day, buzzbaits, topwater baits such as a minnow imitator or frog work great. Once the sun comes up switch to jigs, tube baits or worms work well.

Bait recommendations based on water temp and water clarity; water temp 70 to 80 degrees use topwater baits, frogs, plastics, deep diving crankbaits, spinnerbaits, football jigs, flipping jigs, drop shot, jigging spoons and swimbaits. Lower water temps in the 65 to 70-degree range use shallow crankbaits, spinnerbaits, jigs, smaller worms, topwater baits, buzzbaits, and frogs.

We’ve talked about bass for the most part, but take the same information we’ve outlined here when you make decisions on when and where to go. Some species of fish thrive in warmer water and they can certainly add the excitement of the day. Also, remember that heat will stress fish, so take a quick photo of those trophy fish and release them back into the water. Beyond the fish, take care of yourself and all the anglers fishing alongside you. Drink plenty of water, use sunscreen and above all else have fun! Tight lines all!