The Idaho Department of Environmental Quality issued the alert Saturday afternoon for both counties.
The forecast index is 75.
All open outdoor burning is prohibited in Ada County and the cities within by municipal and county ordinance and in the incorporated cities within Canyon County by municipal ordinance when the AQI reaches 60 or above.
All open outdoor burning is prohibited in unincorporated portions of Canyon County when the AQI reaches 75 or above. Indoor/wood burning is restricted in the City of Boise and Ada County when the AQI reaches 74 or above.