Our Programs

Winter Air PollutionCombating the Brown Cloud

The Problem: The Denver region combats different pollutants in the summer time – ground-level ozone, and in the winter time – carbon monoxide (CO) and particulate matter (PM).  Because of the unique meteorology surrounding the formation of these pollutants in the winter, the Denver area experiences periods where the “Brown Cloud” appears to hover over the metro-area.  The Brown Cloud is not only an eye sore to the community, pollutants that make up the haze are also harmful to public health.

The Program: From November 1 through March 31, at 4:00 p.m., the Air Pollution Control Division (APCD) at the Colorado Department of Public Health and Environment (CDPHE) issues daily air pollution advisories for the seven-county Denver metropolitan area. On days when air quality and/or visibility conditions are exceeding or predicted to exceed standards, the department will call for an “Action Day!” similar to those issued during the summer months for ground-level ozone. Action Days activate mandatory indoor burning restrictions. Action Days also call upon citizens to make voluntary driving reductions. When no Action Day is called for, good conditions exist and are expected, and no mandatory indoor burning restrictions are in place

APCD’s High Pollution Advisory Program urges citizens to do their part to reduce winter air pollution.

Indoor Burning Information and Regulations