http://www.trmichels.com/PeakTurkeyGobbling.htm
Peak Turkey Gobbling Activity Chart
Some of us like to know when peak turkey gobbling activity occurs in the state we intend to hunt, so we know which dates to choose for hunt dates. There are two normal peaks in gobbling activity, one before peak breeding and one after peak breeding. The problem with predicting the dates of these two gobbling peaks is that unlike the rut of many antlered animals, which occurs at approximately the same time every year due to photoperiod, but may be changed by a major difference in weather conditions earlier that year; turkey breeding time-frames (as in many ground nesting birds) are dependent on photoperiod, and to a great extent on spring weather (meteorology/phenology) conditions. Normal turkey breeding dates may be pushed forward by early warm weather and emergence of forage, or be delayed by later than normal cool weather and lack of forage. Turkeys may also re-nest if their first nesting attempt doesn't produce young due to untimely cold or wet weather; this may result in another gobbling peak.