I don't buy into this mild weather malarchy, bright daylight and nothing else gets the mating hormones going.I remember when we had -25 degrees in December one year and I had all my pairs down on eggs so nothing to do with heat. A pigeon regulates its body to the same temperature regardless of weather. When its warm, the feathers open, when its Baltic, they are as tight as a ducks azz. Give your birds a freezing cold bath in the coldest of days and they jump right in ( as long as its bright weather )so they like bright sunny days regardless of temperature imo.