Deviations from normal weather patterns are putting several regions in the U.S. at risk for an uptick of disease-spreading pests as winter turns to spring, according to a new analysis.

A surge in disease-spreading pests like ticks, mosquitoes, cockroaches and rodents is expected in regions that experienced especially warm or wet winters this season, according to the National Pest Management Association’s bi-annual Public Health Pest Index.

These pests can spread dangerous diseases such as Lyme disease, West Nile virus, Salmonella, plague, and hantavirus, said Jorge Parada, medical adviser for NPMA with a focus on infectious disease, in a statement. These types of pests can also trigger asthma and allergies, Parada said.

Warm winters typically allows more rats to survive, while unusual weather patterns — such as snow in New Orleans — can present a host of new pest problems, Jim Fredericks, senior vice president of public affairs for NPMA, told ABC News.

Ticks and mosquitoes survive better when it is moist, so regions that experienced especially wet winters will likely see those pests on the rise during the spring, Fredericks said.

“If the temperatures are above 50 degrees Fahrenheit, ticks will be active and in search of food,” Fredericks said.

Changes in climate — both in terms of warmer temperatures as well as the extreme weather events occurring as global temperatures rise — will have a greater impact on the threats these pests pose in the future, Fredericks said. The range for pests like ticks are also spreading due to warmer temperatures, Fredericks said.

The top U.S. cities named on the pest index include:

Boston: “Brutal” snowstorms and cold snaps pushed rodents indoors in search of warmth and food sources, according to the NPMA. In addition, a forecasted warmer start to spring could give ticks a jumpstart to the season.

Cleveland: “Mild, soggy conditions” during the winter could allow for pest populations like cockroaches and ticks to flourish as temperatures rise, the analysis found.

“The pathogens that they carry that could cause food-borne illness,” Fredericks said, adding that rodent dander and urine can also exacerbate asthma symptoms.

Denver: “A frigid and snow-packed” start to the season will likely drive house mice into homes and businesses, while white-footed mice activity inside structures could increase in rural areas, according to the NPMA.

“The white-footed mouse is actually one of the vectors for hantavirus,” Fredericks said.

Grand Rapids, Michigan: “Record-breaking” snowfall is expected to drive rats and mice indoors, and heavy rain forecasted for the area could lead to a rise in tick populations as temperatures rise, according to the NPMA.

Louisville, Kentucky: Rats and mice are expected to enter structures due to extreme cold and historic snowfall. Tick activity may also begin earlier than usual due to a warm spring.

New Orleans: Historic snowfall in the region sent rats and cockroaches into homes, and mosquitoes are expected to make a “fierce comeback” as temperatures climb, the analysis found.

Salt Lake City: Winter conditions could send house mice and white-footed mice indoors.

San Antonio: “Record-breaking warmth” during the winter allowed mosquitoes, cockroaches and ticks to stay active, and a “pest boom” is expected come spring — with a surge in bites, infestations and pest-related health concerns forecasted.

Seattle: A warm, dry start to winter could lead to an increase in rodent and cockroach activity indoors and an increase in tick populations could occur with the spring rains, according to the NPMA.

Washington, D.C.: A “rollercoaster” winter that started unusually warm and ended in heavy snowfall has made rodent activity climb significantly in the nation’s capital, the report states. Tick populations could surge if spring arrives early.

Florida: The group has issued a statewide warning for Florida, pointing to the Sunshine State’s humid climate that allows disease-carrying pests to thrive year-round, the report stated. Although the winter brought dry, cool conditions, a surge is expected this spring as rising temperatures and humidity create ideal breeding conditions.

“We have all of the mosquito species here,” Ryan Carney, an assistant professor at the University of South Florida’s Department of Integrative Biology, told ABC News. “There’s a huge diversity, over 90 species of mosquitoes. Fourteen of those are anopheles, which spread malaria.”

Mosquitoes are the deadliest animal on the planet, killing more than 1 million people per year from the diseases they carry, and Florida is no stranger to outbreaks of mosquito-borne illness. In 2023, nearly 200 people contracted dengue fever, and there were more than 1,500 cases of Zika in the state from 2016 to 2018, Carney said.

A citizen science project run by USF creates artificial intelligence algorithms to help identify and stop disease-carrying mosquitoes before they are able to infect humans and other large mammals.

“These citizen sciences, especially for mosquitoes, are a way that people can report these sightings of mosquitoes or mosquito bites, and that helps us scientists understand the biodiversity of mosquitoes in the area,” Carney said.