I don't think cold weather plays a roll. Mine layed and hatched eggs in the snow this year. I was shocked to find my hens laying eggs in my dry pound with snow all around them. I was even more shocked to find the eggs where good and hatched out 22 poults from one nest. I get high winds and frost until late May. I always have Turkeys start laying by early February. They are in full production by March. My last eggs are usually October-November.