Colorado city named among worst U.S. cities for allergies, surging 69 spots in national rankings

If you find yourself taking a little more Claritin or Zyrtec this season, this could be why…

Colorado Springs has been named the 15th worst city in the nation for allergy sufferers, a dramatic leap from No. 84 just one year ago, according to an annual report released by the Asthma and Allergy Foundation of America.

The 2026 Allergy Capitals report, which ranks the 100 largest metropolitan areas in the contiguous United States, found that Colorado Springs vaulted into the top 20 after being classified as “better than average” in 2025. The foundation’s rankings are based on pollen scores for tree, grass and weed pollen, over-the-counter allergy medication use and the availability of board-certified allergists.

The city was not alone among Colorado metro areas seeing a sharp climb. Denver jumped from No. 91 to No. 30, also shifting from better than average to worse than average in a single year.

Researchers attributed the surge to tree pollen peaking earlier and at higher concentrations, grass pollen seasons lasting longer, and weed pollen starting earlier and reaching higher levels. The report cited atmospheric rivers, rising temperatures driven by climate change and persistent drought as factors that worsened conditions, particularly across the Western United States.

For the first time, Western cities dominated the top 20 most challenging places for pollen allergies. Boise, Idaho, claimed the top spot as the most difficult city for allergy sufferers, followed by San Diego, Tulsa, Oklahoma, and Provo, Utah.

The full top 20, according to the foundation:

1. Boise, Idaho
2. San Diego, California
3. Tulsa, Oklahoma
4. Provo, Utah
5. Rochester, New York
6. Wichita, Kansas
7. Raleigh, North Carolina
8. Ogden, Utah
9. Spokane, Washington
10. Greenville, South Carolina
11. San Francisco, California
12. Minneapolis, Minnesota
13. Salt Lake City, Utah
14. Richmond, Virginia
15. Colorado Springs, Colorado
16. Little Rock, Arkansas
17. Toledo, Ohio
18. New Orleans, Louisiana
19. Winston-Salem, North Carolina
20. Lakeland, Florida

Health experts recommend that allergy sufferers who do not find complete relief from over-the-counter medications consult with an allergist about other options, including immunotherapy and biologic treatments.