California PK–12 students are headed back for the 2024–25 academic year, and the back-to-school timing overlaps with California’s fire season. While wildfires are a particular risk in the Wildland Urban Interface (WUI), where rural communities meet undeveloped wildland, smoke can travel to densely populated areas—making wildfire smoke a health and safety concern for schools across the state. The risks of smoke are heightened for children, especially young children, for reasons including their higher breathing rate and greater exposure due to outdoor play.

California’s fire season is changing due to climate change: the season is longer, and fires are more frequent and more severe. This year brought extreme temperatures with a very hot and dry summer. The number of wildfires in 2024 so far has already exceeded the state’s five-year average; the acres burned are 55% greater than the average. Over recent years, the number of days with heavy smoke and unhealthy air quality has risen steadily, with spikes observed in Central Valley and Northern California. In 2020, a particularly severe year for fire, 14 counties—8 in the Central Valley and 6 in Northern California—experienced 30 or more days of unhealthy air quality.

In light of longer fire seasons, schools and communities need to be preparing for large fires and far-ranging smoke. Extreme heat and wildfire smoke have disproportionately affected certain communities. For example, lower-income neighborhoods often have less tree cover, which can exacerbate the effects of extreme heat and poor air quality. Children with pre-existing health conditions, such as asthma and cardiovascular diseases, or those living near industrial areas or highways are especially vulnerable. The increasing frequency of poor air quality days due to wildfire smoke, however, is affecting school districts across the board, regardless of the level of student poverty.

Studies have linked wildfire smoke exposure to reduced school performance, and prolonged exposure has been associated with reduced cognitive function in children. Schools have developed guidelines to mitigate the effects of wildfire smoke, including limiting outdoor activities, requiring masks, and using HEPA filters in classrooms. Adhering to these guidelines and developing comprehensive emergency plans for wildfire smoke events remains important. Trees may not be an obvious solution to combatting the effects of wildfire, but they can play a crucial role in improving air quality in addition to regulating temperatures during extreme heat events. However, it is important to choose the right species of trees and plant them strategically.

To counter smoke that may make its way into buildings, researchers and advocates encourage improving indoor air quality in California's schools to protect children’s health. During the pandemic, California invested in air filtration devices for schools. While these funds are expiring, schools can leverage other state and federal funding opportunities. And state investments in building green spaces on school campuses are helping to improve air quality outside and create healthier environments for students and neighborhoods. These and other investments are helping to prepare schools for the changing climate and protect children’s health and education.