If water temperatures have been under 50°F for a time, that particular point on the thermometer becomes important. As waters broach that temperature, panfish turn on. It’s a good time to be on the water. In Tennessee, where water temperatures typically hover in the low-40°F range all winter, 50°F water temperatures might first occur in early or mid-March. But even shallow bays in Wisconsin or New York might not reach 50°F until May.

Early Spring Movements

When the ice goes off northern lakes, some panfish may have been shallow for weeks or months. Water temperature in the main lake typically is around 40°F the day after the ice breaks up. During winter, panfish in northern natural lakes tend to spend most of the winter deep, on 20- to 40-foot flats. In many lakes, panfish arrive in shallow spots during last-ice (late March, early April). Ice fishing late in the season can produce big crappies and bluegills in reedbeds no deeper than 5 feet in some lakes. But in others, panfish won’t arrive until ice leaves the shallows altogether.

If the main lake is 41°F at ice-out, shallow bays can sometimes register as high as 48°F to 52°F, especially after a few days of sunlight. Dave Genz, longtime contributor to In-Fisherman on panfish subjects, follows the sun in spring. “The biggest panfish move shallow first, usually during the first calm, sunny days after ice-out,” he says. “It’s always a big-fish pattern. Sunny days warm the shallow bays, and the lake’s biggest panfish tend to be the first to arrive. Even when ice still covers the main lake, the biggest fish arrive first in bays that have thawed. I’m not a big temperature-gauge guy, but calm, sunny days in early spring are my cues to hit the water. Several days like that always precipitate hot panfish bites in early spring. The first places to check for bluegills, crappies, and perch are bays with wood like stumps, fallen trees, and brush, which seem to absorb additional solar energy. A creek flowing in, bringing warmer water, is another good sign.”

Thermal zones that warm quickest in spring are prime attractions at most latitudes. In states where lakes never ice up, 50°F is still a key temperature. Bob Holmes, an accomplished bluegill guide in Tennessee, says, “...50°F is like an awakening. The water’s been colder than that for months, and it triggers a major feeding spell.”

Holmes spends most of his guiding days on Reelfoot, a natural lake formed by an ancient earthquake. It’s a large but relatively shallow lake, with some holes approaching 20 feet. “Some crappies use those deep areas in winter, but others use shallow, dark-bottom bays, and flats thick with timber. Maximum depth is about 3.5 feet. The dark bottom and wood absorb solar energy, and we can sometimes catch crappies all day, every day, in areas like this during January and February.”

Northern crappies rarely occupy such shallow areas during winter, except in flowages, backwaters, and other riverine environments.

When surface temperatures hit 50°F in shallow bays and coves, especially when temperatures have been colder than that for some time, magic happens in the panfish world. The fish bite like they’ve been starved for weeks, which, in fact, they have been, in some cases. Some panfish remain deep or suspended in the main lake or in the back third of major creek arms in reservoirs in the South, but they tend to bite well. In the North, the most active panfish are shallow at 50°F, using coves and shallow south-facing bays with brushy shorelines.