This year’s tick season could be one of the worst on record, according to federal data and experts.
The Centers for Disease Control and Prevention’s Tick Bite Data Tracker, which uses real-time emergency room surveillance, shows weekly tick-bite ER visits are higher than historic averages in every U.S. region except the South Central states, with the Northeast recording the highest levels so far in 2026.
During the fourth week of April, about 114 out of every 100,000 emergency department visits nationwide were for tick bites — the highest rate for this point in the year since at least 2017, the CDC said. Nationally, the agency estimates about 31 million people are bitten by ticks each year, and roughly 476,000 Americans are treated annually for Lyme disease, the most common tick-borne illness.
“Tick season is here and these tiny biters can make you seriously sick,” said Dr. Alison Hinckley, epidemiologist and Lyme disease expert with CDC’s Division of Vector-Borne Diseases. “That means ticks are out and people are getting bitten, so now is the time for people to take steps to protect themselves and their loved ones.”
While the CDC only tracks ER visits related to tick bites — not tick bites or the presence of ticks overall — the increase indicates that weather patterns, normal year-to-year variation in tick survival, and geographic expansion of tick populations could result in one of the most prolific tick-bite seasons in recent memory.
Is Tick Season Coming Earlier?
Tick season was once relegated to warmer summer months. That’s no longer the case, according to Dr. Jim Fredericks, chief entomologist with the National Pest Management Association.
“As we see this trend over time of these milder winters and kind of shorter shoulder seasons — this spring, it feels like it just goes from winter to summer,” he said. “This allows for a greater proportion of tick populations to survive the winter, even in places where there has been snow cover.”
Warmer weather arriving earlier and lasting longer has enabled ticks to proliferate almost year-round in some areas. And that layer of snow you might expect to kill them off? It serves as more of a cozy blanket.
“Ticks actually do better when there’s more snow rather than less snow because a snowpack is insulating for them,” added Dr. Kathryn Reif, associate professor of parasitology at the College of Veterinary Medicine at Auburn University. “They’re kind of down in that dead layer of plant material where they’re all snuggly warm.”
Why Is Tick Season So Bad This Year?
Beyond a relatively mild winter and the snow-blanket effect, experts also point to what they call the “acorn effect.”
Wildlife that often carry ticks — deer, mice and squirrels — feed on acorns each fall. Oak trees don’t produce the same crop every year; instead, they follow an irregular cycle. A year of heavy acorn production is called a “mast year,” and the U.S. has seen several notably large ones recently, Fredericks said.
When small mammals can eat from a plentiful food source and reproduce more, more ticks can use them as hosts.
“If our wildlife are healthy and have a lot of food, that can certainly make more of them, which is now more hosts for these ticks to feed on,” Reif said.
And because ticks obtain the diseases they carry from mammals like chipmunks, mice and squirrels — not by birth — more of those animals means more potential for disease transmission.
Tick-Borne Diseases on the Move
Lyme disease is often the first illness that comes to mind with ticks, but experts note that ticks are carrying more disease-causing organisms farther than previously recorded.
Ehrlichiosis, anaplasmosis, Rocky Mountain spotted fever, babesiosis, tularemia and tick paralysis are all diseases that can spread to humans and pets.
Lyme, ehrlichiosis and anaplasmosis are especially prevalent in dogs and their owners, Reif said. Their prevalence is also expected to expand in 2026, according to the Companion Animal Parasite Council, which forecasts disease prevalence in dogs with more than 94% accuracy.
Ehrlichiosis and anaplasmosis generally cause flu-like symptoms early on, but if untreated can lead to respiratory and organ failure, excessive bleeding, central nervous system damage and death. Lyme is more varied, with symptoms ranging from fever and rash to facial paralysis, irregular heartbeat and arthritis.
“We have the traditional hot spots where these tick-borne diseases are most common. And as years go on, these zones never really contract — they only continue to expand,” Reif said. “These are definitely diseases on the move.”
How to Protect Yourself From Tick Bites
Prevention is key when it comes to ticks.
If you own property, consult a pest-control specialist on tick-proofing the space — which may include putting up barriers between the lawn and wildlife-accessible areas, keeping grass short, and applying repellents, said Fredericks.
If you have pets, speak to your veterinarian about flea and tick prevention, annual screening, and Lyme disease vaccination, said Reif.
If you spend time outside, you should:
Wear insect repellent.
Cover exposed skin with clothing and proper footwear.
Remove clothing and do a full tick check as soon as you return home.
You should also check your body carefully after coming inside. Ticks tend to find warmer, hidden areas of the body — pay special attention to the hair, ears, back, underarms, waistline, belly button, groin, knees, and between the toes.
Reporting by Mary Walrath-Holdridge, USA TODAY.
