This article was originally published by CityLab and is reproduced here as part of the Climate Desk collaboration.

At times over the past two summers, Seattle experienced some of the worst air quality in the world. With wildfires breaking out in British Columbia, Oregon, and California, the city was hit by smoke from nearly every direction. It caused increased air pollution for 24 days, and on a few occasions, the air was so bad it was considered “unhealthy for all.”

Seattle Mayor Jenny Durkan and her colleagues are grappling with the possibility that this could be a “new normal” for Seattle’s summers. On June 19, Durkan announced plans to create public clean-air shelters that residents can visit on smoky days in the city’s future.