This is a calendar that i used as a pesticide technician to know what was "in season". It works on a calculation of the Growing Degree Days in your area. Many species of plants and insects Calibrate the timing of their emergence with their favorite hosts production of leaves or sap. You can keep track of your areas GDD by using the calculation below, or searching for it using Ecosia.org. 

(Tmax=daily high temp; Tmin=daily low temp; Tbase=50F/10C)