Several studies have observed a seasonal pattern to hair shedding, with a higher proportion of follicles entering the resting (telogen) phase together in late summer, leading to increased shedding roughly two to three months later.

This is separate from pattern hair loss — it's a synchronised, temporary increase, and it typically self-resolves. If you notice your shedding tracker showing a seasonal bump each year, that's a useful pattern to mention to a dermatologist, since it helps distinguish ordinary seasonal shedding from something that needs closer attention.