The length of flea season depends entirely upon the climate of the area that you live in.
In general, fleas become less active when the temperature dips below 70°F. When the temperature gets below 50°F, fleas will go dormant and many of the adult flea population will die.
Fleas are very hardy creatures, however, and they can survive over a long harsh winter. That is because, while many adult fleas will die during cold temperatures, there are many more fleas in the pupa stage of their development that remain encased in a silken cocoon, protected from the harsh conditions.
When environmental conditions are more conducive to their livelihood, the adult fleas will emerge from their cocoon to feed on a host and reproduce, thus continuing the life cycle of the flea population.
