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Grass Pollen Stays Widespread as Seattle Reaches Very High and Southeast Grass Builds

June 14, 2026 by PollenScience Staff

Eugene remained in the top severity band, while high grass readings held around Chicago, Wisconsin, Oklahoma City, Waco, San Juan, Portland, and Colorado Springs. Tree pollen is now mostly limited to the West and Puerto Rico, and mold was mainly a local issue in Austin, Chicago, and St. Louis.

National Overview

Grass pollen is the main burden for allergy sufferers across the broadest part of the country. The West carried the sharpest grass pressure, with Eugene and Seattle both reaching Very High; Portland and Colorado Springs were also elevated. The Midwest remained firmly active around Chicago and Wisconsin, while Oklahoma City and Waco kept South Central grass readings high and San Juan stayed elevated in Puerto Rico.

The Southeast also became more noticeable for grass. Cincinnati, Greenville, and Nashville moved into the high range, even as Richmond and Washington dropped below that mark. That makes the regional pattern uneven rather than quiet: grass is building in parts of Kentucky, South Carolina, and Tennessee while the Mid-Atlantic side of the region looks less intense than last week.

Tree pollen is no longer a broad Southern or Midwestern burden. The remaining elevated tree readings were concentrated in the West, especially Alaska, Colorado Springs, Reno, and Seattle, along with Puerto Rico and Lebanon, New Hampshire. Midwest tree readings dropped below high levels at the available stations, and the Southeast and South Central regions also stayed below high tree levels.

Mold was more localized. Austin remained high, while Chicago rose into the high range and St. Louis stayed elevated. South Central mold was less widespread than last week, with Houston, Oklahoma City, and San Antonio moving lower. Weeds stayed mostly quiet, with no reporting station reaching a high weed level.

High Allergy Burden Locations

Location Allergen Level Drivers
Eugene, OR Grass Very High Grass Family, all types
Seattle, WA Grass Very High Grass Family, all types
Anchorage (South), AK Tree High Alder; Pine Family with air bladders
Austin (Georgetown), TX Mold High Other identified fungi
Caguas (Centro), PR Tree High Other identified tree pollen
Chicago (Melrose Park), IL Grass High Grass Family, all types
Chicago (Melrose Park), IL Mold High Ascospores
Cincinnati (Florence), KY Grass High Grass Family, all types
Colorado Springs (North), CO Grass High Grass Family, all types
Colorado Springs (North), CO Tree High Pine Family with air bladders
Fairbanks, AK Tree High Pine Family with air bladders
Greenville, SC Grass High Other identified grass pollen
Greenfield, WI Grass High Grass Family, all types
La Crosse (Onalaska), WI Grass High Grass Family, all types
Lebanon, NH Tree High Pine Family with air bladders
Madison, WI Grass High Grass Family, all types
Nashville, TN Grass High Grass Family, all types
Oklahoma City, OK Grass High Grass Family, all types
Olean, NY Grass High Other identified grass pollen
Portland, OR Grass High Grass Family, all types
Reno (Sparks), NV Tree High Pine Family with air bladders
San Juan, PR Grass High Grass Family, all types
San Juan, PR Tree High Other identified tree pollen
Seattle, WA Tree High Juniper family, Cedar
St. Louis (Berkeley), MO Mold High Ascospores
Waco (Woodway South), TX Grass High Grass Family, all types

Pollen Drivers

For trees, pine-family pollen carried much of the remaining named burden, especially in Colorado Springs, Reno, Fairbanks, and Lebanon. Alder also contributed in Anchorage, while Seattle's elevated tree reading came from juniper and cedar. Puerto Rico's high tree readings were reported under the broader other-tree category.

Mold was split between ascospores in Chicago and St. Louis and other identified fungi in Austin. Weed pollen did not reach high levels at any reporting station, so weed season still looks early across much of the country.

Weather Context

Warmer weather spread across much of the Midwest, South Central region, Southeast, and Northeast, coinciding with active grass readings in each of those regions. The Southeast also turned wetter, which coincided with a mixed grass pattern: new high readings in Cincinnati, Greenville, and Nashville, but lower readings around Richmond and Washington.

The Midwest was warmer, wetter, and windier, coinciding with steady grass pressure around Chicago and Wisconsin and a rise in Chicago mold. South Central weather stayed warm, but regional rain totals were lower than last week; Austin mold remained elevated while Houston, Oklahoma City, and San Antonio moved lower.

In the West, precipitation increased but remained lighter than in the central and eastern regions. Grass stayed elevated in the Pacific Northwest and Colorado Springs, while tree pollen remained most relevant in Alaska, Colorado Springs, Reno, and Seattle.

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