Standing a few feet over the head of your targeted species, drilling holes in ice with 4 feet of water underneath seems ridiculous. Everybody knows that the warmest water in a frozen lake is down near bottom in deep to mid-depth basins, because water is most dense at about 39°F. Water warmer or colder than that rises. Panfish, as a rule, leave the shallows to trout and pike in winter. Even in reservoirs with open water, in states like Arkansas and Tennessee, most of the panfish move deep—usually somewhere between 20 and 40 feet. But not all of them, and not all the time.

Exceptions to the winter-equals-deep-panfish equation abound, even in the ice-bound states. In-Fisherman Editor In Chief Doug Stange: “In several Iowa lakes I once fished, several series of canals are dredged for homeowners. These canals are no deeper than 5 or 6 feet, yet sometimes draw panfish during winter,” he says. “A typical canal might go straight for 100 yards, then elbow or branch off in another direction for another 100 yards or more.

“Panfish sometimes push all the way to the back end of these features during fall and throughout the ice season. Eventually, they settle into some little pocket of slightly deeper water, or a spot with slightly better environmental stability, or something of that nature, until anglers or pike find them.

“Fishermen find a pocket of panfish on these canals and catch them until they thin them out—or pike move in. Then they catch pike for a few days, and eventually the panfish set up in that spot again. Or not. It really isn’t a stable pattern. But, for those who find it, it’s theirs and theirs alone for several days to a week.”

Dave Genz, professional ice-fisherman extraordinaire, says marginal-ice states like Iowa have more green weeds throughout winter. “The weeds stay green and oxygen counts are higher in states where the ice doesn’t get as thick and snowfall measures less,” he says. “In places like Michigan’s lower peninsula, Illinois, New York, and Nebraska, I’ve found lots of panfish biting in water less than 8 feet deep during January.

“You’re looking for 39°F water,” Genz continues. “When the sun is up, the water under the ice will actually warm up, warmer than the ice itself, late in the season. At times it can reach temperatures up to 44°F a few feet under the ice. That’s why panfish locate right under the ice sometimes. I always thought it was because of food—which is probably a factor—but since I started taking temperature readings with Aqua-Vu underwater cameras, I’ve noticed surprising variations in temperature 2 to 6 feet down. That phenomenon only happens late in the year up in Minnesota or Canada when the sun gets up high in the sky and melts the snow, and water runs through holes in the ice. The rays of the sun penetrate at that point, and the angle of the sun is high enough to actually warm the water just under the ice.”

In more southerly latitudes, that warming under the ice or on the surface of lakes that cooled over the previous months is possible at any point during winter. “In lakes that support vehicle traffic in winter, you won’t find as many shallow patterns in midwinter,” Genz says. “In southern Michigan or northern Indiana, weeds tend to stay green all winter because more ultraviolet light gets through.”