"Asthma Peak Week" Just Got a New Name, and It's Bad News for Anyone Who Thought They Were in the Clear

Key Takeaways

• According to the Asthma and Allergy Foundation of America's newly released 2026 Asthma Capitals report, the organization is moving away from the term "Asthma Peak Week," the third week of September, in favor of "Asthma Peak Season," reflecting data showing elevated risk extends well beyond that single week.
• Research on asthma exacerbation patterns shows ED visits spike starting in September and continue at elevated levels into winter, a pattern consistent with AAFA's report. The September spike is linked mainly to the return to school and the spread of rhinovirus and other common respiratory viruses in classrooms, with the winter rise tracking flu and RSV circulation.
• September still matters as the start of the higher-risk window, with ragweed pollen and rising mold counts as contributing factors alongside the return to school. What AAFA's report emphasizes is that the elevated risk doesn't end after September, it continues into flu and cold season.
• This reframing means a treatment plan built only around getting through September may stop short of the actual risk window, which extends for months rather than one week.

Why the name change actually matters

For years, "Asthma Peak Week," the third week of September, has been the go-to shorthand for the most dangerous stretch of the year for people with asthma. It's a useful, memorable idea, and it's not wrong that September is genuinely dangerous. What AAFA's newly released 2026 Asthma Capitals report changes is the ending point. The organization's data analysis found that asthma peaks aren't confined to one week, or even one month. Elevated risk that starts in September continues into the winter, tracking with the spread of respiratory infections like flu, RSV, and colds.

That's AAFA's reasoning for moving from "Peak Week" to "Peak Season." It's not a minor rebranding on their part. It reflects a shift in understanding of when asthma patients are actually at the highest risk, and it has practical implications for how long a heightened-vigilance treatment plan should actually run.

What's driving the extended risk window

September starts it, and the virus is the bigger piece

The research literature on the September spike points to the return to school, and the close-contact spread of rhinovirus and other common respiratory viruses that comes with it, as the dominant driver, responsible for a large share of pediatric exacerbation hospitalizations in this period. Ragweed pollen reaching its highest concentration of the year and rising mold counts as fallen leaves decompose are real, additional contributors, but they work alongside the viral and back-to-school factors rather than driving the spike on their own.

Respiratory infections keep it going into winter

According to AAFA's report, respiratory infections are a key reason asthma-related emergency department visits stay elevated well past September and into the winter months. As flu and cold season ramps up through late fall and winter, and viruses circulate more efficiently in cold weather and indoor gatherings, that infection burden keeps exacerbation risk elevated long after ragweed season has ended.

I think a lot of patients hear 'September is the hard month' and mentally check the box once October arrives. What AAFA's report is really telling us is that checking that box in October is premature. The infections driving hospitalizations don't peak in September, they build through the fall and often peak later in the winter. If a patient's asthma action plan only accounts for ragweed season, it's missing a big piece of the actual risk period.

— Dr. Robert Tamayev, MD, PhD, Allergy Asthma

What this means for your asthma plan

If your usual approach has been to be extra careful through September and then ease off, this update is a good reason to extend that vigilance further into the fall and winter. That means keeping controller medication use consistent well past ragweed season, staying current on routine respiratory illness precautions, and not assuming that a quiet October means the risk period has passed. For families with children who have asthma, this is particularly relevant, since respiratory infections circulating through schools are exactly the kind of ongoing trigger this extended risk period is tracking.

When to book a visit

Consider scheduling an evaluation if your asthma action plan hasn't been updated to reflect a longer risk window than just September, if your child has had asthma flares tied to colds or the flu in past winters, or if you want to make sure your controller medication routine is built to carry you through the full fall and winter stretch rather than just the ragweed peak.

Disclaimer: This content is educational and does not substitute for medical advice. Always consult your physician for personal medical questions.