US Schools See More Wildfire Smoke Days, Study Finds
October 29, 2026
Wildfire & Schools | October 29, 2026 | 2 min read
US Schools Are Seeing Far More Wildfire Smoke Days, and Buildings Don't Always Keep It Out
A new national study found the number of smoky days at US schools and child care centers has climbed sharply in less than two decades. It also found that being indoors doesn't always mean cleaner air.
What did the study find?
Researchers at Oregon State University analyzed air quality data across the US from 2006 to 2023, published in the journal Environmental Research. The average number of wildfire smoke days per year at public schools rose from 6.8 to 54.4. At child care centers, it rose from 9.4 to 112.2.
Does being inside a school protect kids from smoke?
Not consistently. The study found that buildings offered uneven protection, and some schools recorded higher indoor PM2.5 levels than nearby outdoor monitors on smoke days. PM2.5 is fine particulate matter, 2.5 micrometers or smaller, and it's a main component of wildfire smoke.
What do the researchers suggest?
The study's authors point to schools and child care centers as places where preparedness plans, air filtration, indoor air quality monitoring, and changes to activities during smoke events could reduce exposure. Co-author Molly Kile said HVAC upgrades can be expensive, while portable HEPA filters may be a more affordable option for some buildings.
Prep your home before the next smoke event
What happens in classrooms can happen at home too. A few steps to take now:
- Keep an eye on real-time air quality maps for your area.
- Set your HVAC system to recirculate mode when smoke is in the area.
- Switch to a MERV 13 filter, the EPA-recommended rating for wildfire smoke, if your system can support it. During smoke events, we recommend changing 1" and 2" filters every 30 days.
Sources: Environmental Research (Foster et al., 2026), Oregon State University, Air Quality News.