Fall allergy forecast: Weed, grass pollen to surge in parts of US
AccuWeather’s 2026 fall allergy forecast shows weed pollen will be a widespread concern, while grass pollen remains highest in parts of the East and Midwest.
AccuWeather’s Geoff Cornish and Alan Reppert take a look at what allergy sufferers can expect this fall, including where pollen levels could be highest.
Fall allergy season is ramping up across the United States, with warm and wet weather helping pollen levels climb in parts of the country, especially across the eastern half of the nation.
Grass and weed pollen are the biggest concerns during the end of summer and start of autumn. In 2026, the highest grass pollen levels are forecast in some of the most populated areas of the country, while weed pollen will be a more widespread concern.
Grass pollen forecast
“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.
The East will have the best chance of lingering grass pollen trouble spots, especially where warm nights and enough moisture keep grass growing. The highest grass pollen levels are predicted across the mid-Atlantic and across the Midwest, including areas in and around New York City, Philadelphia, Detroit and Chicago.
In the West, drier weather should help slow grass growth in many areas outside of irrigated locations. The Southeast is expected to have enough dry stretches to keep grass pollen lower than typical for many areas.
For people sensitive to grass pollen, the same basic habits can still help, such as showering after spending time outdoors. Additionally, leaving shoes outside or taking them off immediately after coming inside can limit how much pollen gets tracked indoors.
Weed pollen forecast
Weed pollen will be the bigger fall allergy concern across the country, and could linger into October.
Rainfall tied in part to El Niño will play a role in some of the higher weed pollen this fall, according to Reppert, with the worst pollen levels predicted across the Southeast and southern Rockies. Raleigh, North Carolina; Nashville, Tennessee; Atlanta; Little Rock, Arkansas; Denver; Salt Lake City; and Albuquerque, New Mexico, are all expected to have high weed pollen levels this fall.
“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.
Dry weather in the northern half of the country should help limit weed growth in some areas, keeping the overall season lower than the historical average in parts of that region. Still, warmth across much of the country could allow for periods of stronger pollen spikes.
Rain can bring short-term relief by washing some pollen out of the air, but the break may not last long. In some areas, pollen can increase again in the days after rainfall as weeds use the rainfall to grow and release more pollen.
(Getty Images/Ali Majdfar)
People with fall allergies can take simple steps to reduce exposure on high-pollen days. Keeping windows closed, using air conditioning or an indoor air purifier when possible, checking pollen levels before spending long stretches outside, changing clothes after outdoor activities and showering before bed can help limit exposure to pollen.
People with asthma or more severe allergy symptoms should follow guidance from their health care provider, especially on days when pollen levels are high or symptoms interfere with sleep, work or school.
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