In-Fisherman's

Calendar Periods

In-Fisherman Staff
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FISH ACTIVITY DURING THE 10 CALENDAR PERIODS

Prespawn: The period when fish are on the way to, or in the vicinity of, their spawning areas prior to spawning. During this stage, there can be feeding activity and heavy grouping. Fishing can be good.

Spawn: A brief, variable period linked to the range of preferred spawning temperatures for each fish species. Feeding activity is minimal. Fish of the same species do not always spawn at the same time, however.

Postspawn: The length of the Postspawn Period is variable, depending on water conditions, species of fish, and the sex of the fish. Male fish tend to be more responsive to fishing.

Presummer: A transition period during which fish begin to establish summer patterns.

Summer Peak: During this short period most fish of a species establish summer patterns. The Summer Peak often begins after several days and nights of hot weather. Competition for abundant food spurs fish activity and good fishing.

Summer: Fish may stick to location patterns established during the Summer Peak. Algae blooms, cold fronts, abundant forage, and other factors may make fishing difficult. Fish activity patterns and fish location are predictable, however.

Postsummer: This period occurs at the end of summer when days and nights bring consistently cooler weather. Fishing often is good.

Fall Turnover: A short period when the lake is in turmoil from mixing of cold surface water and warmer water below. Turnover homogenizes lakes that have thermoclined (layered accordingto water temperature) in summer. Fishing is usually poor.

Cold Water: This period occurs twice, once in early spring and again during late fall. Fish establish specific patterns. Fishing can be very good.

Winter: This is the coldest water of the year. Frozen water is common in northern regions.


While Calendar Periods always occur in order, their length varies for each species based on such things as geography and body of water type. The periods are not the same for each species. Largemouth bass, for example, are often in the Spawn Period when pike are in the Presummer or Summer Peak Period.

Calendar Periods are important because they pinpoint where fish are located and how active they are.