Tick season is more than a date on a calendar.

Weather and location matter

Ticks can be active when temperatures are consistently above freezing and ground is not snow-covered. Encounters are most likely in spring, summer, and fall, but favourable conditions can allow activity at other times. Ticks also turn up outside places where they are already known to be established.

Look up the destination, not only home

Lyme disease is associated with infected blacklegged and western blacklegged ticks. Risk varies geographically and changes over time. Consult public-health guidance for the destination, especially when travelling between states, provinces, or countries. Maps help plan prevention; they cannot determine whether one particular tick is infected.

A North American seasonal planning framework

• Spring: refresh the kit, review pet prevention, and read local guidance before yard cleanup.
• Summer: make protection and return-home checks part of travel, camping, and everyday outdoor routines.
• Fall: keep the routine going during leaf cleanup, hunting, and warm-weather walks.
• Winter: reassess during thaws and before travel; do not assume the calendar eliminates exposure.

Plan ahead for pet travel

Tell your veterinarian the destination and departure date. Ask whether your existing prevention covers the relevant parasites and whether any testing or other measures are needed. Keep a copy of the treatment schedule with your travel information. Avoid replacing a prescribed product with an unfamiliar item bought across the border.

Use primary sources for updates

In the United States, start with CDC and your state health department. In Canada, use PHAC and your provincial or territorial public-health authority. For Mexico travel, check destination-specific advice and local health services. For a tick you have found, eTick can help with identification. Recheck sources when travel plans change. This guide is a dated research summary, not a live local surveillance service.

United States: different regions, different ticks

Blacklegged ticks are important in the eastern U.S.; western blacklegged ticks occur along the Pacific region. Lone star ticks are widely distributed in the Northeast, South, and Midwest. Rocky Mountain wood ticks occur in the Rocky Mountain region. Geographic ranges overlap, so use CDC maps and state health sources rather than assuming only one species is present.