Trends Affect the Crappie Spawn

To get a significant and steady warming of water to a depth of 3 to 5 feet, it usually takes a steady increase in air temperature, some sunny days, and moderate winds. To heat shallow areas as deep as 3 to 5 feet under totally calm conditions, it takes longer and sunnier days than in similar areas with wind exposure under cloudy skies. As a result, wind-blocked but deep coves may be suitable for spawning later than those exposed to some wind, even though the latter have higher surface temperatures.

The 3- to 5-foot zone is important because it takes stable conditions at these depths, rather than at the surface, to trigger crappies to spawn. They spawn when the temperature at nest depth and slightly deeper is stable and increasing, near 68°F. Males may move to nesting areas at temperatures between 62°F and 67°F and build nests at 58°F to 62°F degrees, but stable increasing conditions at nest depth are usually necessary. Very shallow nests are the first to be lost if a cold front hits after eggs are laid.

An anglers’ axiom claims that the north sides of coves and lakes tend to get the most sun and warm fastest in early spring. This is partially true if trees or bluffs shade the southern shores for a significant portion of a spring day. But without shade, both sides receive equal amounts of sun, and the average and recent wind directions determine which side is warmest. Wind blows the warmer surface layer to the downwind side. If the wind has been from the north, southern shores may be warmer. Coves stretching north and south and blocked from strong winds may have one side warmer than the other, depending on prevailing wind direction. When planning a spring trip, plot recent wind trends to predict warmer locations.

Air temperatures don’t solely control water temperatures. But steadily increasing average air temperatures are often the most available predictor of a steady and adequate water-temperature rise sufficient to promote a spawn.

Inflows influence the process as well, and can cause mixing at different levels. Warm inflows can actually become the surface layer, while cold inflows may sink and move under warm surface layers. If they run deep enough, cold inflows may not slow a spawn at all. This is where a “down-temp” gauge pays dividends.

Rain and Other Factors

In spring, gentle warm-front rains often bring warmer water that floats on top of lakes and ponds, accelerating the warming process. But rain from taller clouds may come down cold, chill the surface, mix away warm surface layers, and sink to make nesting areas inhospitable to crappies for several days.

Local conditions influence warming: Light-colored vertical surfaces like an adjacent bluff or even a building can reflect additional sunlight into local areas, hastening the warming and creating earlier local spawning conditions. Outflow from a deep aquifer can supply warm water all year. In the Austin, Texas area, springs flow at 68°F to 72°F.

Anglers should monitor average air temperatures and measure surface temperatures in likely spawning coves. A continuous and steady increase in the average day and night air temperature, combined with several days of clear skies, is a good sign. Also consider the wind and rain history of the area, and look for gradually increasing surface temperatures in the coves you plan to fish. At the lake, use a temperature meter with a cable to the probe, like the Cline Finder from Catalina Technologies, to check how deep the warming effect has reached in areas protected from wind.