A sustainable city has a healthy and vibrant environment. The City of Westminster is working to maintain and protect our environment and is prioritizing air quality. Learn about air quality—indoor and outdoor health—and what you can do to help ensure that the environment stays healthy.  

What is Westminster’s Air Quality Right Now? 

See our local air quality and learn how the Air Quality Index (AQI) works.  

Check out more air quality monitoring data and maps here

Get Informed About Air Quality

Sign up for Air Quality Notifications and Register for Ozone Alerts 

Air Quality Index and Particle Pollution AQIChart

Learn more about the AQI and healthy actions here 


Ground-level ozone pollution is different than the ozone layer of the atmosphere that protects us from harmful radiation from the sun. When ozone is lower in the atmosphere, it causes harmful pollution. Ground-level ozone pollution is created when oxides of nitrogen (NOX) mix with volatile organic compounds (VOCs) in the presence of sunlight. Generally, VOCs are things you can smell like cars, trucks, trains, and busses that run on gas.

Negative impacts of ozone pollution include:  

  • Stinging eyes and throat.
  • Chest pains.
  • Coughing.
  • Breathing difficulty.

What Can I Do? Here's How to Take Action on Air Quality:


Learn more about air quality, ozone, and what you can do to impact and improve it!  

Visit these activity guides for additional information on how and when to adjust your activity levels depending on air quality:  

Outdoor Air Quality

Common Sources of Outdoor Pollution and How to Protect Yourself and Our Community 

Below are some immediate steps you can take to protect your health and to help improve outdoor air quality here in Westminster and the region.  


  • Avoid outdoor physical activities: If you can see it, smell it, or taste it – you shouldn’t breathe it. Face coverings not specifically designed to filter smoke do little to prevent breathing in the fine particles and harmful chemicals transported by wildfire smoke. 

  • Purchase an air purifier 

  • Keep windows and doors closed and If you have an HVAC system, use the highest level of filtration recommended by the manufacturer and replace filters regularly 

  • Check out the National Weather Service air quality smoke forecast 

  • Prepare: visit the EPA’s Smoke-Ready Toolbox for Wildfires webpage 

Landscaping equipment and care 

  • Use an electric lawn mower and earn a rebate through the Mow Down Pollution program 

  • Switch other lawn and garden equipment from gas to electric power!  

  • Refrain from mowing your lawn until after 5:00 p.m. 

Healthy Transportation 

  • Fuel in the early mornings or night: When you fill up your car mid-day, or in the daylight, gas emits oxides of nitrogen (NOx) and volatile organic compounds (VOCs) which mix in the presence of sunlight, forming  ozone. If you fill up your car when it's not sunny (early morning or night) these fumes have time to dissipate and they don’t form ozone.  

  • Adjust your driving habits: Take fewer car trips, carpool, use public transportation, telecommute, or walk or bike to your destination 

  • Turn off your car instead of idling while waiting. 

  • Participate in the EcoPass program to enjoy unlimited rides on most regular RTD transit services, including the SkyRide service to Denver International Airport at no charge 

  • Track your travel 

  • Drive an Electric Car (EV).  

Burning Wood

Indoor Air Quality 

Did you know that common household activities, such as cooking on a gas stove or using certain types of household cleaning products can trigger poor air quality inside your home.  

Indoor air quality refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants.  

The Colorado Department of Public Health and the Environment groups indoor air quality concerns by the following: 

  • Comfort issues 

  • Sick building syndrome 

  • Building-related illnesses. 

Exposure to indoor air pollutants can have immediate or long-term health impacts, depending on the type of pollutant, a person's sensitivity to it and their age and health.  

Common Sources of Indoor Air Pollution 

Below is a list of typical sources of indoor air pollution and some tips for what you can do to address them.  

Gas stoves and fireplaces 

Household chemicals 

Infiltration of outdoor pollutants