i just moved out to phoenix this year, i lived in st.louis for 18 years. Yes the pigeons can handle the cold, but the squabs can not! At about 5-8 days of age the adults can hardy cover the squabs which have zero feathers to keep them warm. People who breed during the winter either heat there loft or have heat lamps. The pigeons may or may not even breed. Im stopping soon and will pick up in the fall. Its not a problem for me since even in the dead of winter i still have highs in the 60 and very seldom hit 32 degrees, if but only for a few hours.