Crappie

It’s possible to predict within a few degrees what temperature the water will be. Water temperature is influenced by surrounding air temperatures. Take a reading of the water late in the day (usually its highest point). During the following days and weeks, the average daily air temperatures control what the water temperature will be. If the water reads 55°F, then nights with a low of 45°F and days with a high of 65°F won’t change the water temperature much. At that point, to warm the water, look for highs of 68°F or more, with nighttime lows over 50°F.

One way to predict water temperature during spring is to keep track of daytime highs every day and add them. Divide that by the number of days to get an average daily high. Then add the nighttime lows and divide that by the number of nights, to arrive at an average low. Add the two averages together, divide by two, and the result should be pretty close to the prevailing water temperature in the main lake. Solar influences can raise the temperature higher in shallow water, though; so to predict water temperatures in shallow bays, add about 2°F to 4°F to that total during cloudy, windy weather, and up to 10°F during sunny, calm weather.

A sample calculation: Over a three-day period, the high temperature reaches 50°F the first day, 54°F the second, and 56°F on the third. Add those together (160) and divide by 3 to arrive at an average daily high of 53.3°F. If the low temperatures those three days were 38°F, 42°F, and 44°F, the three-day total would be 84. Divide that by 3 to arrive at an average low for the three days of 28°F. Add the high average to the low average (53.3 + 28 = 81.3), dividing the total by 2 to arrive at an approximate water temperature of 40.65°F. So, in shallow bays, the water temperature could be 42°F to 50°F, depending on prevailing weather. Use simple calculations like these to keep track of water temperature and to key panfish events when you can’t get on the water.