Pollen expected to surpass historical averages in 39 states this year: Report

The Hill

20-03-2025

Pollen counts will likely exceed historical averages in 39 states this year as warmer weather starts to blanket much of the U.S., meteorologists are warning.
Experts are urging those who suffer from seasonal allergies to take heed and prepare for an intense allergy season that could last longer and linger into the fall months.
'About one-quarter of U.S. adults have been diagnosed with seasonal allergies, and nearly one in five children have seasonal allergies,' Alan Reppert, a senior meteorologist at AccuWeather, said in statement.
'Millions of people living with seasonal allergies will be struggling with more intense symptoms that will likely stick around longer this year in many areas,' he added.
Reppert attributed these complications to the wet and warm weather patterns anticipated later this year, which he projected would lead to these unwelcome spikes in pollen.
He and his colleagues also looked to the colder and snowier winter that much of the country experienced, which will now be upended by warmer spring temperatures overall.
The hotter weather would be consistent with springs in recent years and foster longer growing seasons and earlier starts to allergy season, added Brett Anderson, a senior meteorologist and climate expert for AccuWeather.
Thanks to changing climate conditions, Anderson said in a statement that seasonal allergy seasons are lasting one to four weeks longer in many parts of the country, in comparison to 50 years ago.
'There will be variability year to year depending on spring temperatures, storm tracks, and additional moisture from tropical storms and hurricanes, but the overall trend is clear,' Anderson said.
Tree pollen, the first of three primary allergens in the U.S., begins in the spring once ground temperatures climb to 40-45 degrees Fahrenheit, according to an AccuWeather report. Next in line is a wave of grass pollen in the late spring and early summer, followed by weed pollen in the late summer and fall.
'The cold start to the year in much of the eastern half of the country will keep tree pollen levels lower to start, but there can still be a week period of very high levels,' Reppert said.
The meteorologists projected that the worst of the tree pollen would strike the Gulf Coast, the Central Plains, the Northern Rockies and the Pacific Northwest.
Tree pollen levels may be higher than the historical averages across a 2,000-mile-long zone, spanning 22 states, per the report.
However, Reppert noted that dry weather in the Southwest through the spring should ultimately help the season end there after a ferocious start.
The Northeast and the Pacific Northwest will likely face the most severe grass-related allergy seasons, particularly in June and July amid a probable warm and wet start to summer, according to AccuWeather.
As for weed pollen, these allergens are expected to do their worst and peak in July across the Tennessee Valley, but they may also usher in a second peak due to a rise in moisture toward the end of the summer, the report found.
As the planet continues to warm, Anderson warned that the trend of longer and more intense allergy seasons will likely persist over the next decade. Contributing to this phenomenon is the burning of fossil fuels, which releases carbon dioxide into the air and creates warmer air — which in turn, can hold more moisture, he explained.
'The combination of more rainfall that can boost plant growth, higher spring temperatures, longer growing seasons, and more carbon dioxide in the atmosphere triggering increased pollen production is the reason why more people are experiencing seasonal allergy symptoms for the first time, and many longtime allergy suffers are dealing with worsening symptoms,' Anderson added.