have a circumpolar distribution. They breed in coastal Alaska, Canada, and Greenland, as well as in northern Scandinavia, Russia, southern Novaya Zemlya and northern Siberia. In winter, snowy owls can be found in Canada and the northern United States, sporadically further south into the U.S. Snowy owls are generally solitary and territorial.
Snowy owls are migratory. However, migration in this species is unpredictable and likely related more to prey abundance than seasons or weather. In general, snowy owls move nomadically, and breed when and where prey is abundant. Approximately every four years, many snowy owls irrupt into the northern United States during the winter, presumably because prey is scarce further north.
—animaldiversity.org I was lucky to witness such an irruption. At one point there were up to 5 snowys on Jones Beach at the same time. Most winters there is only one or if lucky, maybe two.