Can Ticks Survive Winter in a Yard?

Leaf litter is the key to overwintering survival. It insulates ticks against the extreme temperature swings of an exposed surface, and once snow accumulates on top of it, that snow layer adds further insulation, keeping ground-level conditions closer to freezing than the open air well above it. Research summarized by the Cary Institute and a University of Maine study found blacklegged tick overwinter survival did not vary significantly across different parts of the state, suggesting this insulated micro-environment reliably protects them across a range of winter conditions.

A single hard freeze or a cold snap is not enough to eliminate a yard's tick population, because most ticks aren't exposed to the full brunt of it — they're sheltered under leaves and snow where temperatures stay milder. Killing an exposed tick generally requires sustained exposure to very low temperatures, a condition leaf litter and snow cover are specifically effective at preventing. This is the direct answer to the hopeful assumption that 'a cold winter will handle it' — in a typical New Hampshire winter, it largely doesn't.

Adult blacklegged ticks don't hibernate the way many insects do. NH DHHS confirms ticks remain active as long as there's no snow cover and temperatures stay above freezing, and TickEncounter notes adult activity extends from October through May whenever daytime temperatures allow. That means a January thaw or an unusually mild February afternoon can bring adult ticks back out questing — and adults are notably one of the life stages most likely to be carrying Lyme disease bacteria, which makes winter complacency a real risk rather than a theoretical one.

Since leaf litter is the main shelter ticks rely on to survive winter, fall yard cleanup — clearing leaves, especially along yard edges, near stone walls, and around play areas — meaningfully reduces overwintering habitat before winter sets in. Pet prevention should continue through the colder months rather than pausing seasonally, per CAPC's year-round guidance, since adult ticks remain a real risk on mild winter days. A professional yard treatment timed around fall cleanup and spring reactivation targets the population at both ends of its winter survival cycle.