Culex pipiens provides the life cycle model for most of the domestic Culex in temperate areas. Inseminated adult females from the last generation of the season, build fat body by feeding on carbohydrates and enter hibernation in fall. The females pass the winter in diapause and do not become active during periods of warm winter weather. Hibernating females are common in basements, outbuildings and subterranean enclosures. Like Culex restuans , the females congregate near moisture and move their resting location during the winter to remain in a humid atmosphere.
Mortality can be extensive during periods of winter drought.
Females emerge from hibernation during May and begin depositing egg rafts in suitable habitat. Populations of this mosquito usually peak during August but breeding continues well into September. The adults from the last generation of the season lose all interest in blood meal hosts but will move in and out of overwintering sites during periods of mild fall weather. Larvae rarely persist in breeding habitats after females have entered hibernation. Culex pipiens can be found in a fairly wide range of larval habitats but are generally associated with water that has a high organic content.