Fall Turnover Bass Fishing: What the Science Says—and Anglers Get Wrong

When bass fishing gets tough in the fall, one explanation seems to come up more than almost any other. The lake is turning over.

Fall turnover occurs when cooling surface water mixes with the deeper layers of a lake, breaking down the temperature and oxygen boundaries that previously concentrated bass during summer. The fish don’t necessarily stop feeding, but they can spread across a much greater area, making familiar fishing spots less reliable. Finding them means understanding how the lake has changed.

I’ve heard fall turnover blamed for everything from muddy water and scattered fish to dead vegetation, bad smells and a bass bite that seemingly disappears overnight. Like a lot of anglers, I’ve also wondered how much of that is really turnover—and how much is simply fishing folklore.

Some of those observations have a basis in what’s actually happening beneath the surface. Others give turnover far more credit—or blame—than it deserves.

The biggest misconception may be that bass simply stop feeding.

They don’t.

What changes during fall turnover is the environment the fish have been using all summer. Once those familiar temperature and oxygen boundaries disappear, bass suddenly have far more freedom to move. The fish may still be eating aggressively, but finding them can become a much different challenge.

Turnover is also just one part of the broader fall bass transition, as cooling water, changing vegetation and shifting forage continue reshaping where fish spend their time. 

To separate turnover fact from fishing folklore, we asked Shawn Good, a fisheries scientist with the Vermont Fish & Wildlife Department, what actually happens inside a lake—and then looked at how Bassmaster Elite Series pros Seth Feider and Jay Przekurat adjust when those changes affect their fishing.

Fall Turnover: Myths vs. Reality

What Is Fall Turnover?

During summer, many deeper lakes become stratified into distinct layers.

Warm, less-dense water sits near the surface, while colder water remains below. Separating those layers is the thermocline, an area of rapidly changing water temperature that can also help define where adequate dissolved oxygen and comfortable temperatures overlap.

That creates fairly predictable zones where bass and baitfish can live.

Fall changes that arrangement.

As colder air and wind cool the lake’s surface, the upper layer becomes denser. Eventually its temperature approaches that of the water below. Wind and wave action can then mix the water throughout much or all of the water column.

That mixing is fall turnover.

The result is relatively similar temperature and oxygen conditions from top to bottom. The boundaries that concentrated fish during summer become much less important.

One important correction to conventional fishing wisdom: turnover generally doesn’t happen overnight.

Good says the process commonly occurs gradually over several weeks, and not every lake behaves the same way. Shallower lakes can mix relatively quickly, while deeper systems may take considerably longer.

Signs a Lake May Be Turning Over

• Surface and deeper-water temperatures are becoming similar.
• Water suddenly looks murkier, especially after wind.
• Foam, leaves or other debris are collecting on the surface.
• Baitfish appear across many depths on sonar instead of forming a distinct layer.
• Some lakes may develop a swampy or rotten-egg smell.

Does Fall Turnover Stop Bass From Biting?

Turnover may make fishing seem tougher, but Good says that doesn’t mean bass have stopped feeding.

The problem is often that anglers continue fishing the places where the bass were during summer.

“Bass locations become less reliable as the fish become more transient,” Good said. “Turnover doesn’t stop fish from feeding.”

Once temperature and oxygen become more uniform throughout the water column, bass have fewer physical reasons to remain within the relatively narrow depth ranges they occupied during summer.

Their world effectively gets bigger.

Good describes it less as bass suddenly “scattering” and more as their comfort zone expanding. Fish can move more freely because acceptable temperature and oxygen conditions are available across a greater portion of the lake. At the same time, dying vegetation and moving baitfish create another reason for bass to relocate.

That means anglers who keep returning to productive summer spots may conclude turnover has shut down the bite when the bass have simply moved.

“I’ve heard anglers blame slow fall bites on the turnover, but it’s actually just that the fish have moved,” Good said.

The answer is straightforward: move with them.

Does Fall Turnover Reduce Oxygen in a Lake?

Another common misconception is that turnover somehow “kills” the lake’s oxygen.

In many lakes, the opposite is closer to the truth.

During summer stratification, deep water beneath the thermocline can become oxygen-poor because it is isolated from the atmosphere and from the wind and wave action that mixes oxygen into surface water.

That can produce hypoxic conditions—very low dissolved oxygen—near the bottom.

Fall mixing allows oxygen-rich surface water to circulate deeper into the lake.

“Fall turnover fixes that when winds and waves mix surface waters and oxygen through the whole water column,” Good said.

Anglers occasionally encounter cloudy water or even a swampy or rotten-egg smell during turnover. Good says bottom water can sometimes contain hydrogen sulfide produced by decomposition in oxygen-poor sediments. Turnover can bring some of those gases toward the surface, but the concentrations are generally too low to harm fish.

How Can You Tell if a Lake Is Turning Over?

No single floating weed or patch of dirty water proves turnover is occurring.

Good says anglers should look for several indicators working together: surface temperatures approaching those found deeper in the lake, suddenly murky water after wind, foam or floating debris, baitfish showing on sonar throughout the water column instead of in a defined layer, and occasionally a swampy smell.

Electronics can be particularly useful.

I’ll increase the sensitivity on my Humminbird unit and idle across deeper water. When baitfish appear scattered through many depths rather than holding within a distinct zone, that’s another indication the lake has mixed.

The important thing is not to become fixated on proving that turnover has occurred.

What matters is recognizing that the old summer depth patterns may no longer apply.

Where Do Largemouth and Smallmouth Bass Go During Turnover?

Turnover affects both species, but Good says largemouth and smallmouth often respond differently.

Smallmouth are generally more comfortable roaming open water and cooler environments. As fall progresses, they often shift toward rock, gravel, steep breaks, humps and other hard structure, particularly where those areas provide access to deeper wintering water.

Their diet may shift more heavily toward schooling baitfish as crayfish become less active.

“Find schools of bait and you’ll probably find smallmouth bass,” Good said.

He recommends finding roaming fish with faster presentations before slowing down with techniques such as tubes, drop-shots or blade baits once a productive depth and type of structure has been identified.

Largemouth are more closely associated with vegetation, wood and shallow cover.

As weeds begin dying, largemouth frequently relocate from deteriorating vegetation to the healthiest remaining green patches, wood or areas where baitfish have concentrated.

That can make finding the right remaining cover far more important than simply finding vegetation.

Green weeds continue producing oxygen and providing cover, while dying vegetation does neither particularly well. Good says largemouth can stack around those remaining productive patches and edges.

Fall Bass Fishing Checklist

• Stop fishing summer history. Bass may no longer be restricted to the depths they used around the thermocline.
• Cover water. Moving baits can help locate active fish before you slow down.
• Follow the bait. Bass may move as forage shifts with changing vegetation and water conditions.
• Look for the best remaining cover. For largemouth, healthy green vegetation, wood and productive edges can become especially important.
• Keep deep water in the equation. Steep breaks, humps and structure near deeper water can remain productive, particularly for smallmouth.
• Let the fish tell you where they went. Don’t assume a slow bite means turnover shut them down.

How to Catch Bass During Fall Turnover

We asked the experts how they adapt to changing conditions in the fall turnover in order to keep catching bass.

Seth Feider Goes Shallow

Bassmaster Elite Series pro Seth Feider spends much of his year fishing northern natural lakes, so fall turnover is something the Minnesota angler has encountered plenty of times.

His response is decisive.

“I commit to the bank 100% once I know a lake is turning over,” Feider said. “I’m a shallow-water angler, and I feel very comfortable during the fall.”

Because the fish can move and become less predictable after summer stratification disappears, Feider concentrates on shallow cover and keeps moving until he finds active fish.

His go-to presentation around visible targets is a 5/16-ounce Black Sheep Custom Tackle Lil’ Flipper Jig paired with a chunk-style trailer. The relatively compact jig allows him to work around shallow cover without constantly fouling in loose pieces of dying vegetation.

On lakes without substantial vegetation, Feider looks for hard cover such as boat docks suitable for bass fishing, laydowns and riprap.

Where vegetation remains, he targets blown-in mats, lily pads, reeds and the healthiest remaining milfoil.

He also keeps a moving bait ready for the water between obvious targets.

“I’ll have something rigged up to cover water that is in between the visual targets I’m fishing,” Feider said. “Since most of my baits are in 4 feet or less, and many times in a foot or less, I like to use a 3/8-ounce Z-Man EVO ChatterBait.”

The individual lure matters less than the underlying strategy: Don’t wait for fall bass to come to you. Go find them.

Jay Przekurat Keeps Deep Water Close

Wisconsin native and Bassmaster Elite Series pro Jay Przekurat approaches turnover somewhat differently.

He wants bass to have deep water nearby.

“I like fishing in areas of a lake that are close to deep water, whether that be a steep drop that is close to some sort of cover like rock, grass, gravel or even sand,” Przekurat said. “As long as there is deep-water access, I’m happy, as those areas usually hold the most and best bass in the fall, especially during turnover.”

He generally avoids expansive shallow flats that sit a long way from deeper water.

That fits with the larger lesson of turnover fishing. Bass may have fewer temperature and oxygen restrictions than they did during summer, but they still relate to useful structure, cover, forage and security.

Przekurat relies heavily on moving baits to locate those fish.

“It’s hard to beat an umbrella rig and moving baits this time of year like jerkbaits and swimbaits,” he said. “Covering water allows you to find the active schools of bass, and they are willing to chase down your bait as they are feeding up for winter.”

4 Baits for Finding Fall Turnover Bass

Once turnover eliminates the predictable summer zones, covering water becomes increasingly important. These four presentations can handle a wide variety of fall conditions:

1. Spinnerbait: A spinnerbait can be cast long distances and worked through a wide range of depths and cover. I carry extra blades, swivels, clevises and beads so I can change blade combinations as conditions change. A 1/2-ounce Buckeye Lures Select spinnerbait is a good starting point because it remains relatively compact while providing enough weight for long casts.
2. Swim jig: A 1/4- or 3/8-ounce swim jig excels in water roughly 6 feet deep or less, particularly around remaining vegetation. If bass are short-striking, changing trailer size or profile can make a difference. I'll often alternate between a 4-inch Yamamoto Swimming Senko and a bulkier Shinobi Grub.
3. Crankbait: Crankbaits are another efficient way to locate groups of active fall bass. Select a bait that runs deep enough to occasionally contact remaining vegetation or cover. Line diameter can fine-tune running depth: lighter line generally allows the bait to run deeper, while heavier line can keep it shallower. I commonly start with 15-pound Seaguar InvizX fluorocarbon and adjust from there.
4. Jig: A jig remains one of the most versatile options when bass concentrate around isolated weed clumps, laydowns, docks or other hard cover. A 1/2-ounce black-and-blue jig paired with a Yamamoto Yama Bug can be worked shallow or deep and quickly or slowly depending on how the bass respond.

RELATED:How to Fish Seawalls for More Fall Bass

Stop Fishing Yesterday’s Bass

Fall turnover isn’t a switch that suddenly makes bass quit eating.

It changes the lake.

The thermocline disappears. Oxygen and temperature become more uniform. Vegetation dies back. Baitfish move. Bass gain access to water they may not have used during summer, and familiar concentrations of fish can become much less predictable.

Good says one of the biggest mistakes anglers make is continuing to fish “recent history” instead of adapting to those changing conditions.

That may be the most useful way to think about turnover.

Don’t worry about whether the lake has become impossible to fish. Assume the fish have changed addresses until you prove otherwise.

Keep moving. Follow the bait. Find the remaining cover and useful structure. And remember that those bass still have to eat.

The challenge isn’t convincing them to feed.

It’s finding where they went.