Air quality alerts use color-coded categories to show when pollution levels may be unhealthy. Code Orange is unhealthy for sensitive groups, while Code Red is unhealthy for everyone. Code Purple means ...

Add Yahoo as a preferred source to see more of our stories on Google. Delaware is under a "code red" air quality index on July 16 for airborne particles and a "code orange" for ozone due to smoke from ...

Today's air quality is worse than forecasters projected in Washington DC, going beyond Code Red into Code Purple. Forecasters initially believed air quality would be at its worst Friday with an AQI ...

TORONTO, ON- JULY 15 - A swimmer checks out the view of the smoke from Northern Ontario forest fires that has the City of Toronto skyline shrouded in haze as viewed from Humber Park West in Toronto.