2025 Asthma and Allergy Foundation of America Allergy Capitals: Pollen and Air Quality Trends

Longer allergy seasons and rising pollen levels are creating new challenges. Learn how to address these changes and improve the air quality in your home.

If you’re one of the millions affected by seasonal allergies, you know just how challenging allergy season can be. The 2025 Allergy Capitals report, developed by the Asthma and Allergy Foundation of America (AAFA), reveals the cities where living with allergies is toughest, and highlights the importance of taking proactive steps to manage your home environment. Here’s what you need to know.

Emerging trends in allergens

One of the biggest takeaways from the Allergy Capitals report is the impact of climate change on allergy season, which now starts earlier and lasts longer.1 Rising temperatures are causing plants to produce more pollen, and that pollen is becoming increasingly allergenic.

If you’ve wondered, “Why are my allergies so bad?,” the persistent growth of pollen-producing plants may be a significant factor. Shifting climate patterns, including diminishing snowfall and milder winters, intensify this challenge further. Some regions now face tree, grass or weed pollen exposure throughout the entire year.

The worst states for allergies

For the third year in a row, Wichita, Kansas, is the most challenging city for living with seasonal allergies due to its higher than average tree and grass pollen levels, higher than average use of over-the-counter allergy medicine and limited access to allergy specialists. Following closely behind are New Orleans, Louisiana; Oklahoma City, Oklahoma; Tulsa, Oklahoma; and Memphis, Tennessee, which round out the top five worst allergy cities. These cities, along with many others in the Southern and Eastern U.S., face worsening conditions as climate change extends pollen seasons and increases allergen intensity.

Cities on the West Coast are also feeling the impact. For instance, cities in California like Sacramento, Bakersfield and Fresno jumped dramatically in the rankings due to increases in grass and weed pollen levels.

Even if you don’t live in one of the top allergy capitals, allergens travel.² Pollen particles can drift for hundreds of miles, and once they find their way inside your home, they can linger and make everyday living uncomfortable.

Best cities for allergies

Not all cities face the same challenges. Some rank as the least challenging cities for allergies, benefiting from environmental or geographical advantages. Places like Boston, Massachusetts; Salt Lake City, Utah; Akron, Ohio; San Diego, California; and Cleveland, Ohio experience fewer high-pollen days and generally have lower allergen levels, making them more favorable for those looking to minimize exposure to seasonal triggers.

Types of pollen and their impact

The types of pollen that dominate any given locale can also affect allergy severity. Trees, grasses and weeds all produce allergens at different times of year, contributing to the fluctuating intensity of when allergy season peaks. For example, tree pollen is typically most active in early spring, while grass pollen often peaks in late spring and summer. Weed pollen, including notorious ragweed, tends to dominate in late summer and fall — but as the report notes, these cycles are now overlapping, resulting in more year-round allergens.

Practical steps to prevent allergens indoors

If outdoor air is becoming more challenging for you, focusing on indoor air quality is essential. By taking action within your home, you can help reduce allergens and maintain a comfortable environment for your family.

1. Use high-efficiency air filters

Investing in high-efficiency air filters, like Filtrete™ Air Filters, is crucial. Our Filtrete™ MPR 1000 - 1085 Allergen Air Filters are Certified Asthma & Allergy Friendly® by the Asthma and Allergy Foundation of America (AAFA) and Allergy Standards Limited (ASL). They are designed to capture microscopic particles and allergens, including mold, dust, pollen and pet dander. Regularly replacing air filters (at least every 90 days for 1” filters and every 12 months for 4” or 5” deep pleat filters) ensures they work effectively, particularly during high-pollen seasons.

2. Control pollen entry points

To help reduce allergens, limit outdoor allergens from entering your home. Track daily pollen levels to determine when it’s best to keep windows closed and rely on indoor ventilation systems. On high-pollen days, avoid outdoor activities during peak times, often in the morning and early evening.¹

3. Prioritize indoor cleanliness

Pollen can easily cling to clothing, shoes and even pets. Vacuum frequently with a HEPA-filter vacuum, and wash bedding, curtains and upholstered fabrics regularly to minimize allergen buildup. Use microfiber cloths to tackle dust without redistributing particles into the air. Small habits, like removing shoes at doorways, can also reduce the introduction of outdoor allergens.

Looking ahead

Asthma and Allergy Foundation of America (AAFA)’s findings on the length and intensity of pollen seasons make it clear that air quality challenges are mounting. Yet, individuals and communities can take proactive steps. Whether you live in one of the worst states for allergies or a region ranked among the best cities for allergies, investments in air quality improvement strategies can help. From tracking pollen trends to changing high-efficiency air filters, every effort counts in creating a healthier indoor environment.

By staying informed, prepared and proactive, you can better adapt to the growing complexities of air quality this year and beyond.

Sources:

1. “2025 Allergy Capitals” Asthma and Allergy Foundation of America. 2025 (PDF, 3.9 MB)

2. “Tracking a New Forecast: Pollen Edition” Climate Program Office. 2024