The required Air Emergency for the Mendenhall Valley has been officially canceled after air quality levels returned to healthy ranges, according to the City and Borough of Juneau.
Officials thanked residents for their cooperation and patience during the Air Emergency, particularly given the ongoing cold weather conditions. While calling an Air Emergency during a cold snap may appear counterintuitive, city leaders emphasized that such decisions are driven by public health requirements and air quality data rather than temperature alone.
Why Air Emergencies Are Called in Juneau
Under the federal Clean Air Act of 1970, communities like Juneau are required to continuously monitor air quality and immediately follow an approved response plan when pollution reaches unhealthy levels. Air quality monitoring and regulatory oversight in Juneau are conducted by the Alaska DEC Division of Air Quality.
Air quality issues in Juneau are generally limited to the Mendenhall Valley and occur only under specific weather conditions. These problems are most commonly associated with wintertime temperature inversions. During an inversion, warmer air settles above cooler air near the ground, trapping pollutants close to the surface and preventing normal air circulation. This can lead to a rapid buildup of fine particulate matter that poses health risks, especially for children, seniors, and individuals with respiratory conditions.
A Rare but Necessary Measure
Juneau has not experienced air quality levels severe enough to trigger an Air Emergency since 2019. However, officials note that in past years, certain winter seasons have seen as many as 12 Air Emergencies due to persistent inversions and stagnant air.
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City officials acknowledged the inconvenience these emergencies can create for residents and emphasized that the decision to call an Air Emergency is never taken lightly. They also recognized the community’s ongoing engagement and discussion around air quality issues.
With conditions now improved, officials encouraged residents to enjoy the rest of the weekend safely and warmly while remaining mindful of air quality advisories during future cold-weather events.
