Squirrel mating season generally occurs twice a year:

• The first mating season is in late winter to early spring, typically between December or January through February.
• The second mating season happens in late spring to early summer, around May through July to August.

During these periods, males actively court females with chasing and vocalizations. After mating, females undergo a gestation period of about 38 to 46 days. This results in births usually in early spring (February to April) or late summer (August to September) depending on the season they mated. Different species may vary slightly, but for example, eastern gray squirrels mate mainly from December to February for the spring litter, and again from May to June for the summer litter. Female squirrels typically have one or two litters per year with 2 to 7 babies each time.