Millions of Americans are being urged to “keep windows and doors closed,” limit time outdoors, and rethink their daily routines as air quality alerts spread across parts of Colorado, California, and Florida this week.
The warnings, issued through the National Weather Service (NWS) and regional air quality agencies, are not blanket statewide advisories—but they still affect major population centres, including Denver, Los Angeles, and Miami, meaning millions of people are in the danger zone.
Where the Alerts Are in Place—And Until When
In Colorado, an “Ozone Action Day Alert” is in effect across multiple counties in the Front Range urban corridor—including Denver, Boulder, and Fort Collins—from Monday afternoon through to Tuesday afternoon.
In California, the South Coast Air Quality Management District has extended an alert covering parts of Los Angeles County, including Downtown L.A. and the San Gabriel Valley, lasting until at least midday Tuesday…