Warming temperatures caused by climate change have allowed for the expansion of tick habitats, with populations moving farther north. An increase in the number of days above freezing has also expanded their reproduction period.
Studies connecting tick populations and climate change still need further data to produce more accurate results, said Matt Cahillane, an environmental health specialist with NH Healthy Climate. To verify those results, especially at the local level, researchers must collect observational data – meaning going out on the field and collecting ticks for a long period of time.
“A model needs to be tested, and we're not able to test these models with the information we have now,” he said.
But local labs that track ticks and tick-borne diseases have been identifying some general trends.
BeBop Labs, a nonprofit organization in New Hampshire identifies two primary types of ticks in the state: black-legged ticks (also known as deer ticks) and American dog ticks. Black-legged ticks are more likely to carry Lyme disease. According to the Centers for Disease Control and Prevention, New England has the highest rate of Lyme disease in the country.
For more tick prevention tips, check out this guide from NHPR.
BeBop Labs’ data shows the peak for black-legged ticks is shifting earlier from May to April. Their overall numbers, though, have remained constant throughout the years.
“But, the dog tick does change every other year, peaking on the odd year. So 2025 would be a high number of dog ticks,” said Kaitlyn Morse, BeBop Labs executive director. American dog ticks are rarely Lyme disease carriers.
The University of New Hampshire converted its former COVID-19 testing lab to the Collaborative Core Wet Lab, which is now offering tick testing services, after the university noticed a “growing interest from the public about tick testing,” said Shyloh Favreau, UNH Cooperative Extension Diagnostics Services Program Manager and graduate student.
Since it started testing ticks in April, the lab has already processed 63 tests “and the numbers are increasing,” Favreau said.
While they don’t have any field data on tick populations in New Hampshire, they’ve “seen strong public interest and response since launching our tick testing service,” he said. “That tells us ticks—and the diseases they carry—are a growing concern for many people across the Granite State.”
But there are still gaps in public health interventions, both on the individual and community level, Cahillane said.
Beyond short-term repellents and long-term clothing treatments, “being able to identify and avoid tick habitat is probably one of the most effective things you can do,” he said. That type of education still needs to be expanded in the state.
“Rather than showing people a picture of New Hampshire with a very colorful view of tick populations, I'd like to show them a picture of that in their neighborhood or nearby their school,, and help them identify that so they can then make good, informed choices,” Cahillane explained.
State-level policies to help protect vulnerable groups should also be explored, Cahillane said, such as requiring children to bring repellents to school and providing outdoor workers training and repellents free of charge.
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