Boise, Idaho makes its debut in the top spot of the annual Allergy Capitals report from the Asthma and Allergy Foundation of America (AAFA). Boise’s rank as the most challenging U.S. city to live in with seasonal pollen allergies, followed by San Diego, California, signals a trend westward in the 2026 ranking.
Those two cities made a huge jump, after they had been ranked 95th and 97th in the 2025 report. The nonprofit’s annual report is largely based on last season’s data from the top 100 most populated metropolitan areas in the lower 48 states.
“There were quite a few shake-ups this year,” AAFA’s research director Hannah Jaffee tells Allergic Living. “While we always expect some movement with pollen year-over-year, this year’s report features a number of cities in the Western U.S. among the Top 20 for the first time ever.”
Following are the top 10 on AAFA’s Allergy Capitals list:
- Boise, ID
- San Diego, CA
- Tulsa, OK
- Provo, UT
- Rochester, NY
- Wichita, KS
- Raleigh, NC
- Ogden, UT
- Spokane, WA
- Greenville, SC
Wichita, Kansas, which had been in the top spot for the past two years, fell to sixth.
In contrast, the bottom end of the 100 cities indicates the least challenging places to live with pollen allergies.
The annual rankings are based on annual pollen counts for tree, grass and weed pollen. As well, they factor in the use of over-the-counter (OTC) allergy medicine, and the number of allergists in a community.
Allergy Capitals: Long Pollen Seasons
Extended pollen seasons in 2025 are to blame for western metropolitan areas climbing up the rankings, Jaffee explains. She points to several strong storms with intense rainfall as a likely cause.
“The wet spells from storms can make plants grow faster and bloom earlier because the extra rain and warmer weather encourage vegetation,” Jaffee says. That “often leads to more pollen in the air.”
Boise and San Diego scored higher due to tree pollen peaking earlier, grass pollen starting earlier and lasting longer, and weed pollen lasting longer and peaking higher, the report states. Boise also has a low availability of allergy specialists.
The 2026 report points to climate change for fueling weather events, which in turn ratchet up pollen production.
In fact, the city of Boise has launched a climate action guide for its residents after experiencing “one of the warmest winters on record.”
Texas: Big Pollen Improvement
In other areas where the pollen seasons have gotten shorter, those cities have dropped in the rankings.
At the bottom of the list, Houston, Texas, has been crowned the least challenging city for 2026. It had been in the 26th spot in 2025.
McAllen, Texas, exemplifies the effect of shorter pollen seasons. It has fallen to 92nd in 2026 after maintaining space in the top half of the annual list for multiple years. McAllen has gradually made its way down the rankings since holding the top spot in 2018 and 2019.
Shorter tree and weed pollen seasons, as well as a slight increase in allergists, boosted McAllen’s ranking, Jaffee says.
“Nearly all of the Texas cities we analyze for the report made significant drops down the list this year due to shorter pollen seasons,” she says.
Managing Allergy Symptoms
Regardless of where your city lands in the annual rankings, chances are those affected by pollen will be seeking relief. And, that allergy relief will be needed for a longer period of time, according to AAFA.
“Pollen seasons are getting longer and more intense all across the U.S. This means allergy symptoms may start earlier and last longer,” Jaffee says. She stresses seeing an allergist to develop a treatment plan for combatting seasonal allergy symptoms.
Monitoring pollen levels and reducing pollen exposure, especially on those high pollen days, can help patients to manage symptoms. Jaffee also recommends starting OTC allergy medications two weeks before the pollen season starts to trigger symptoms in your area.
For the full list of city rankings, analysis of the data collected, and tips for managing symptoms, visit allergycapitals.org.
Related Reading:
Finding Pollen Allergy Relief: What Pill, Spray or Shot is Right?
Why Climate Change Is Making Pollen Allergies Worse Than Ever
