At 42,956 fire alerts in 2025 so far, this year’s Canadian wildfires are the worst in over a decade, with the exception of 2023, when there were 105,746 alerts.

Though wildfire smoke was to credit for poor air quality earlier in the week, Wednesday's alert is due to high-levels of ozone in the air.

Smoke impacts began in northern Wisconsin Tuesday morning and will spread south through the state by July 31. Air quality may briefly improve on July 31 before smoke returns to northern areas on Aug. 1, the DNR reports.