Maine's Tick Crisis: Cases Surge in Warmer Winters

Maine is experiencing a significant increase in tick-borne diseases, with 2025 marking a record year for reported cases. Milder winters and wetter conditions, exacerbated by air pollution contributing to global warming, have allowed tick populations, particularly the blacklegged tick, to thrive and expand their range northward. This expansion is directly linked to a rise in vector-borne illnesses, including Lyme disease, anaplasmosis, and babesiosis.

Cases of anaplasmosis and babesiosis, both presenting flu-like symptoms, shattered records in 2024 and 2025. Lyme disease numbers also saw a substantial increase, with most infections concentrated in four midcoast counties. The warming climate is pushing white-tailed deer, the primary hosts for blacklegged ticks, further north, intensifying the transmission risk to humans. As people increasingly spend time outdoors during milder winters, the opportunities for tick bites and subsequent disease transmission rise.