Bass are confusing creatures. If you've spent much time trying to catch them, you already know that. One day you can't keep them off your lures. Come back to the same lake a week later, and it seems like every fish has packed a suitcase and left the state. Bass don't travel, of course, at least not out of their home waters, but their moods change often, which is why bass that were so active one day may seem like they have taken a vacation the next time you go fishing. More than likely, something in their homes has changed. Those changes are probably the result of a change in the water temperature or the season. Both play a major role in how bass behave.
Although bass adjust to changes in their environment, they're easier to catch during certain times of the year because they're easier to find and more willing to eat. That's why fishing can be so good in the spring and early summer and again in the fall. But Ken Cook, a retired fisheries biologist and a professional bass angler, said it's a mistake to say bass prefer one season or another or that they "like" a certain temperature range.
"Bass are cold-blooded, so they are more active in warmer water because their metabolisms are faster. Their bodies use more energy, so they need to eat more often," the 1991 Classic champ explained. "But that doesn't mean they aren't active at all in cold water. They just eat less when they're cold. Humans are similar because we need to eat more when we're more active because we burn up more energy."
Water temperatures change as the seasons change, and although temperature and seasonal variations both play different roles in bass behavior, the two are linked. We all know that lakes, rivers and ponds are colder in the winter, hotter in the summer, and somewhere in between in the spring and fall, but do you know bass move as the seasons and temperatures change? That's why we catch them in shallow water sometimes and in much deeper water at other times.
Confused? That's okay. Even Cook, a 14-time Bassmaster Classic qualifier, didn't fully understand how natural variations in weather and seasons affect fish. Nobody really has all the answers. But based on his lifelong experience as a bass angler and biologist, he had a good understanding of where to find bass as the seasons change and as the water temperatures rise and fall.
"They really don't move that far. It's more of an up and down movement. They go shallow and deep all within the same relatively small area as the seasons change, but they don't migrate from one end of the lake to the other," he explained.
As winter gives way to spring and longer, warmer days heat the water, bass start thinking about spawning, so they move into shallow water because bass eggs need sunlight and warmth in order to hatch. Bass eat more often in warmer water, which makes catching them seem pretty easy sometimes. They stay shallow — typically less than 8 feet — until hot summer days push water temperatures into the high 80s. That's when they start to move out to deeper, cooler water where they stay until the shallower water starts to cool again in the fall.
Food is what really dominates the lives of bass. In the spring and fall, the "grocery store" is usually close to the shoreline and around cover like aquatic grass, rocks and docks. Small fish, crawfish, frogs and other creatures are most abundant and most active in shallow water, so that's where the bass will be.
"A primary reason they go to deeper water in the summer and winter is that it's more stable. There are fewer temperature and oxygen level fluctuations, which bass don't seem to like," said Allen Forshage, director of the Texas Freshwater Fisheries Research Center. "Shad also go out to deeper water, and they're an important food source for bass. If a lake has shad, the bass tend to follow them in the summer and winter. Even bluegill will move out to deeper water during those seasons."
How deep do they go? It depends on the lake, but they can stay shallow if a few basic needs are met, or they could go to cover that's 25 feet or deeper. Cook caught spotted bass that were 60 feet below the surface in some deep, clear lakes in Arkansas, but Forshage said there is virtually no oxygen below 15 feet in most Texas lakes in the summer.
"Oxygen is a limiting factor. Bass and all fish need it to survive, so in many cases, they can't go any deeper than 15 feet," he said. "It depends on the lake or the region of the country."
He adds that those bass that do stay shallow in the summer seek darker, cooler water when it gets hot. That can be shade provided by a dock, aquatic plants or a fallen tree. Cook said bass in clear lakes will often retreat to deep water in the summer to find that shade if they have food and oxygen, but bass living in murky water will often stay close to shore throughout the summer.
For much of the year, temperature really isn't that important. Bass can tolerate high and low temperatures pretty well. Cook said he only pays attention to his boat's thermometer when it's very hot — above 85 degrees — or very cold — which to him is anything below 50. But if it's between 55 degrees and 85 degrees, temperature really doesn't affect bass behavior all that much. They'll usually be in shallower water.
Remember, the air temperature doesn't have any effect on bass.
"As the water starts to cool again in the fall, forage fish such as shad move shallow, so the bass follow. In many cases, shad move toward the backs of long coves and bays, so the bass are in those same places," explained Cook.
As the days shorten and the air temperature falls, the water starts to get cold. Once the temperature reaches 50 degrees, the bass start moving to deeper water where they'll spend most of the winter. Although bass eat less in the winter, they still have to eat something occasionally. That's why catching bass in the winter can be tough; but it's not impossible. When Cook fished in the winter, he liked to spend time on the water after a couple of warm, sunny days have raised the water temperature a little. A few degrees difference can really put the fish in the mood to eat.
"You have to keep in mind that in the winter, bass don't need to feed much at all, so don't expect to catch a bunch. If you can catch a couple in a day, you've done pretty well," he explained.
Of course, if you catch bass any time you go fishing, you can consider yourself fortunate … maybe even good. After all, it takes more than luck to understand how bass relate to water temperature and the changing seasons. It takes practice and lots of it. The more you fish, the better you'll be at finding and catching bass, no matter the time of year.
Originally published September 2007. Ken Cook, quoted in this article, passed away in 2016.