According to the latest 2026 environmental reports and American Lung Association data, Anchorage, Alaska frequently ranks as the major US city with the cleanest air. This is due to its geographical isolation, low population density, and the consistent flow of fresh air from the North Pacific. In the continental United States, Honolulu, Hawaii and Bangor, Maine are top contenders, benefiting from sea breezes that "scrub" the air of pollutants. Interestingly, several cities in the Pacific Northwest, such as Bellingham, Washington, also rank highly due to strict local emissions standards and frequent rain that washes particulate matter from the atmosphere. Conversely, even though California has many polluted inland valleys, coastal cities like Salinas often make the "cleanest" list because the Pacific winds prevent smog from settling. For small towns, Waimea, Hawaii currently boasts some of the lowest particulate matter (PM2.5) readings in the entire country.