I've done some research that says middle of the winter and middle of the summer are the hottest times, but it can be anytime. Where I hunt, it seems to be Feb. and Sept. You'll notice you see more Boars hanging with the sows at certain times of year than others. The boars usually live a solitary life except when the girls are ready. I ahve a few different sow in heats for sale on my site if you want to check them out.