Nothing is isolated. Smoke from a wildfire doesn't check a map before it crosses a border -- in mid-July 2026, smoke from roughly 200 active Ontario wildfires plus fires in northeast Minnesota was pushed south into the US Great Lakes and Northeast, pushing air quality to "unhealthy" and "hazardous" readings in states with no fires of their own. The real evidence for that isn't a single number -- it's the pairing below: how much local wildfire activity a US state actually has, next to how bad its air quality actually got. Honest limitation: EPA's own official bulk air-quality dataset (AQS) has a real ~6-month processing lag -- its county-level data below is current through May 31, 2026, so it doesn't cover the July 2026 event yet. The table below it uses AirNow, a separate near-real-time EPA feed, to show the actual event directly.