Lyme Disease Cases Lyme by State Lyme Distribution Tick Distribution Tick Activity Forest Age WUI Population Deer Population Climate Data

Winter Temperatures & Tick Activity Data

Comparative data on winter conditions and tick behavior (1996 vs 2022)

Winter Tick Activity Data:

Blacklegged ticks (Ixodes scapularis) don't entirely disappear in winter. Research from the Cary Institute shows that adult ticks can be active on winter days when temperatures rise above 35°F (1.7°C).

The Cary Institute has collected 25+ years of data on tick activity patterns in various seasonal conditions.

Winter Temperature Data (1996 vs 2022)

1996 Winter Temps
2022 Winter Temps
Tick Activity Threshold (35°F)

Winter Days Suitable for Tick Activity

1996
  • ~14 days above 35°F in winter
  • Recorded winter tick activity: Low
  • Average tick season length: 205 days
  • Observed tick activity start: Mid-April
2022
  • ~32 days above 35°F in winter
  • Recorded winter tick activity: Moderate
  • Average tick season length: 237 days
  • Observed tick activity start: Late March

*Data based on Cary Institute's 25+ years of tick monitoring in Dutchess County, NY. Temperature data represents average winter conditions in the Northeastern United States.

Blacklegged Tick Data (1996-2022)

Observed Tick Patterns:

Source: Data from Cary Institute of Ecosystem Studies tick monitoring program (1996-2022).

References: Ostfeld, R. et al.; LaDeau, S. et al.; Cary Institute of Ecosystem Studies research database.