S.S.
lately, i have come to believe that squirrels can breed about anytime there is a lot of food available to them.
A few years ago and after a very poor fall season, i hunted in mid january and found every old beech tree just full of young squirrels. these were litters that were still together. there had been a huge mast crop that fall but very few squirrels found.
like you, i have taken squirrels that were pregnant that seemed to be out of season.