Air Quality Status and Monitoring

Air Quality Status Map 

This map displays the NowCast AQI values, which are short-term air pollution averages (one-hour) that can reflect changing air quality conditions. The NowCast AQI uses the same color and scale as the AQI and can provide a rough estimate of how hour-to-hour pollution levels compare to 8-hour or 24-hour EPA health standards. NowCast AQI values change rapidly and should not be confused with official daily air pollution averages. These changing values can be used to help determine if the current hour is a good time for outdoor activities. The averaging times produce a “lag time” in reflecting current conditions, which can change on an hour-to-hour basis.  For instance, if conditions are changing rapidly, such as when a dust storm occurs and PM₁₀ concentrations are very high, the AQI will most likely show green for “good” air quality for that hour and possibly for hours to come.  By the same token, the AQI may show as red for “unhealthy” conditions long after a spike in PM₁₀ has passed.  That is why MCAQD also calculates values for current conditions, which better represent the hour-to-hour air pollution levels.

The NowCast AQI value displayed on the WebMap is the highest value that is being reported from the monitoring site for either ground-level ozone or particulate pollution. The AQI values for any of the monitored pollutants can be found by clicking on the AQI bubble for a site. This may be helpful as varying populations have different sensitivities to unique pollutants. 

As a general rule, AQI values under 100 are considered acceptable air quality levels. AQI values between 100 - 150 for a given pollutant denote the potential for members of sensitive groups to experience health-effects related to that pollutant; however, the general public should not be affected. If AQI values are calculated to be between 150 - 200, it is possible for some members of the general public to experience health effects, and members of sensitive groups can experience more serious health effects. AQI values over 200 denote unhealthy air quality conditions for all members of the public.

Please utilize the following links for more information regarding AQI basics, how to use AQI Values, and the health effects of air pollution. 

Map Navigation Guide

Each of the top left drop-down menus operate and can be searched independently. Below is how each drop-down menu functions:

Layers – Select an option to view a map layer (AQI, pollutant, or wind speed/direction). 

Sites – Select an option to open a pop-up window with details about a monitor location and historical concentration data.

Links – Select an option to download current, 5-min, or trend data reports for all monitor sites. 

Hover over any monitor symbol on the map to reveal site monitor location and pollutant overview information. Select the monitor symbol to view a pop-up with details about the monitor and to download historical concentration data. 

The Data time indicator on the top right is the date and time of when the last monitoring data were received. 

Access Current Air Quality Status Map >>