Tree Pollen Remains Intense Across Much of the U.S. as New York and New Jersey Worsen

Tree pollen is still the main problem for allergy sufferers this week. The worst current tree pressure is in the Southeast, where six of seven reporting stations reached High, and in the Northeast, where all four current stations did the same. The Midwest also remains firmly in tree season, with all six current stations at that level as well.

What changed most from last week is that the Northeast got worse while parts of the South Central region slipped slightly from last week’s tree peak without becoming quiet. New York and northern New Jersey shifted into a more consistently rough tree week, while several Texas and Oklahoma stations stepped down one severity band on trees but still remained elevated. Out West, tree season has not disappeared, but it has cooled off: only Eugene is still at High, while the rest of the current Western stations sit at Moderate.

Outside of trees, there are only a few categories that look truly active right now. Grass is still mostly early-season or localized, except for a sharper pocket in the Southeast, where Cincinnati (Florence) hit Very High and Greenville reached High. Weeds are mostly quiet across the country, with Greenville the only station still reaching High. Mold is not broadly elevated coast to coast, but there are a few places where it could still be troublesome, especially Tampa at Very High, plus Chicago, St. Louis, and Oklahoma City at High.

Puerto Rico should also stay on sufferers' radar. San Juan tree pollen moved up to Very High this week after sitting at High last week, while Caguas and Mayaguez continued to post elevated tree and grass levels. Mayaguez also held onto an elevated mold season.

Where Allergy Pressure Increased

If you felt worse in the Northeast this week, the data backs that up. Armonk, New York City, and Union, New Jersey all moved up to High tree pollen from Moderate or Low, while Olean stayed there. That turned the New York and New Jersey corridor into the clearest week-over-week worsening zone for tree allergy sufferers.

The Midwest did not see the same kind of broad tree jump, but it did hold onto a solidly active tree pattern. Appleton, Austin, Chicago, Greenfield, Omaha, and St. Louis all stayed at that level this week. On top of that, Chicago and St. Louis both climbed from Low mold to High, which means some Midwest sufferers likely dealt with a rougher mix than last week.

The Southeast remains one of the tougher places to be this week, even if it did not broadly worsen. Tree pollen stayed elevated in Greenville, Marietta, Richmond, Tampa, Washington, and Cincinnati (Florence), while grass also became more noticeable in a smaller pocket led by Cincinnati and Greenville.

Main Drivers

Oak is still the biggest tree story nationally. It is the allergen showing up most often at elevated levels in the Southeast, and it was also the main driver of the Northeast jump, reaching High at three stations there this week after not doing so last week. Maple and box elder also remain part of the problem, especially in the Northeast and Midwest, where they continue to show up prominently across multiple stations.

Mulberry is another tree allergen worth watching, especially in the Midwest and Southeast, while poplar and cottonwood are still contributing in both regions as well. For sufferers in Texas and Oklahoma, oak remains important, and the region is still very much in tree season. Austin and Houston fell from High to Moderate, and Oklahoma City and Tulsa slipped from Very High to High, even though San Antonio (East) is still at Very High.

Away from trees, the clearest non-tree issue is localized rather than widespread. The Midwest mold uptick is being driven mainly by ascospores, while the Southeast grass pocket is concentrated rather than broad-based. In other words, if trees are your main trigger, this is still primarily a tree week; if mold or grass is your trigger, the trouble spots are more isolated.

Weather Context

The weather shift helps explain some of the movement. The Northeast turned much warmer than the week before, which lines up with the stronger tree pollen week in New York and New Jersey. The Midwest also warmed up and got wetter, which fits the mold increase in Chicago and St. Louis.

The West moved the other direction, turning cooler and wetter, and that lines up with tree pollen backing off to mostly Moderate levels outside Eugene. The Southeast stayed warm and fairly dry, which helps explain why tree pollen is still broadly troublesome there. In Texas and Oklahoma, warmth is still in place, and tree season still looks active, even if a few stations slipped from last week’s top-end severity.