This is where pollen is forecast to surge in the US this fall

Seasonal allergy sufferers beware: This fall is looking like a pollen bomb in many parts of the United States, due to increasingly warm and wet weather .

More than two dozen eastern and midwestern states are projected to feel the worst effects, according to forecaster AccuWeather’s latest report.

These regions will see the highest amount of weed and grass pollen, typically dominant in late summer and early fall.

“For grass pollen, we start to lose the worst of it in August and early September, but things can still be high in parts of the East due to ample moisture and warm overnight temperatures,” AccuWeather Senior Meteorologist Alan Reppert said in a statement .

The highest grass pollen levels are predicted in major cities, including Detroit, Michigan, Chicago, Illinois, Philadelphia, Pennsylvania, and New York City.

Concerns about weed pollen could linger into October, with rain tied to this year’s El Niño climate pattern helping raise levels across the Southeast and southern Rockies.

Cities with some of the worst levels include Raleigh, Nashville, Atlanta, Little Rock, Denver, Salt Lake City and Albuquerque.

“The warmth in much of the nation will help to keep things average and even bring a few days of strong, high peaks over the rest of the nation,” Reppert said.

Ragweed is the biggest culprit of fall allergies, with a single plant releasing up to a billion grains of pollen, according to the Cleveland Clinic .

This pollen can travel hundreds of miles, worsening respiratory symptoms for people with asthma and lung conditions.

Frost can kill this ragweed – but climate change is helping to push the first frost of the fall later in the year.

Close to 180 cities see the first freeze an average of a dozen days later than in the early 1970s, according to the non-profit Climate Central .

Climate change is also helping plants to bloom earlier and make more pollen, the American College of Allergy, Asthma and Immunology warns.

“The data is clear, and millions of seasonal allergy sufferers have noticed the changes. The seasonal allergy season in America is expanding at both ends,” AccuWeather Climate Expert and Senior Meteorologist Brett Anderson said in March.