Worst Cities for Allergies in 2026: The AAFA Allergy Capitals List

Every year, the Asthma and Allergy Foundation of America (AAFA) ranks the 100 most-populated U.S. metro areas by how challenging they are for people with pollen allergies. In the 2026 Allergy Capitals report, released in March 2026, Boise, Idaho, took the top spot, and several Western cities jumped into the top 20 for the first time.

This guide lists the top 20, explains how the ranking works and why the West moved up, and covers what you can do wherever you live. For more, see our seasonal allergy guides.

Jump to: Quick answer · Top 20 for 2026 · How cities are ranked · Why the West moved up · Managing allergies anywhere · FAQ

Quick answer

• Top 5 for 2026: Boise, ID; San Diego, CA; Tulsa, OK; Provo, UT; and Rochester, NY.
• What’s measured: tree, grass and weed pollen scores, over-the-counter allergy medicine use, and the number of board-certified allergists.
• Big shift: the top cities used to cluster in the Southeast, but in 2025 Western cities saw more pollen spikes and longer seasons, especially for grass and weed pollen.
• Each year’s list uses the previous year’s pollen data, so the 2026 ranking reflects 2025 conditions.
• Your own triggers matter more than your city’s rank. An allergist can test which pollens you react to.

The top 20 Allergy Capitals for 2026

Source: AAFA 2026 Allergy Capitals report. The average total score across all 100 metro areas was 80.63. Atlanta, long known for heavy spring pollen, ranked 34th in 2026. See the full ranking on AAFA’s site.

How cities are ranked

AAFA ranks the 100 most-populated Metropolitan Statistical Areas in the contiguous 48 states, based on 2024 U.S. Census Bureau population estimates. Each city is scored on:

• Pollen scores for tree, grass and weed pollen.
• Over-the-counter allergy medicine use.
• Availability of board-certified allergists and immunologists.

The factors aren’t weighted equally. Because the list covers only the 100 largest metro areas, a city can drop off simply because a growing city replaced it in population, not because allergy conditions improved. AAFA notes this happened to Scranton, Pennsylvania, which ranked 19th the year before.

The report is AAFA’s independent research and was supported by Opella, the maker of Allegra, with data help from several companies.

Why Western cities moved up

AAFA says the top Allergy Capitals have historically been in the warm, humid Southeast. In 2025, though, Western areas had more pollen spikes and longer seasons, especially for grass and weed pollen. The report points to three weather factors, all tied to long-term climate change:

• Atmospheric rivers: storms in late 2024 brought heavy moisture inland. Well-watered trees produce more pollen the next spring, which may explain jumps for Boise and Spokane.
• Warmer temperatures that lengthen growing seasons.
• Drought, which can affect how far pollen travels and how long it stays in the air.

This fits wider research showing North American pollen seasons have grown longer and more intense. See do seasons affect allergies?

Managing allergies wherever you live

1. Know your triggers. Get tested so you know whether trees, grasses or weeds bother you, and when their seasons peak where you live.
2. Start medicine early. Allergy medicines work best when started before the season begins.
3. Watch pollen counts and limit outdoor time on high days.
4. Keep pollen out: close windows, use air conditioning, and shower and change clothes after time outdoors.
5. Ask about long-term treatment such as allergy shots or tablets if medicines aren’t enough.

Our pollen avoidance guide covers these steps in detail. For more on treatment, read allergy drops vs shots, and if you have tree pollen allergy, see birch pollen and food cross-reactions.

This guide is general information, not medical advice. Read our medical disclaimer.

Frequently asked questions

What is the worst city for allergies in 2026?

Boise, Idaho, ranked number one in AAFA’s 2026 Allergy Capitals report, followed by San Diego, Tulsa, Provo and Rochester, New York.

How does AAFA rank allergy capitals?

It scores the 100 most-populated U.S. metro areas on tree, grass and weed pollen, over-the-counter allergy medicine use, and the number of board-certified allergists. The factors aren’t weighted equally.

Why are Western cities now on the list?

AAFA says that in 2025, Western areas had more pollen spikes and longer seasons, linked to atmospheric rivers, warmer temperatures and drought, all connected to climate change.

Will moving to another city cure my allergies?

Not necessarily. Every region in the ranking has tree, grass and weed pollen; only the timing and amount differ. Knowing your triggers and getting the right treatment usually matters more than where you live.

Where is Atlanta on the 2026 list?

Atlanta ranked 34th out of 100 in the 2026 Allergy Capitals report.

Sources

• Asthma and Allergy Foundation of America. 2026 Allergy Capitals report. March 2026.
• Asthma and Allergy Foundation of America. How the top 100 U.S. cities rank for seasonal pollen allergies.

Last reviewed: October 21, 2026.