An overview of air monitoring sources USED during a wildfire smoke event

Air quality may change quickly depending on wildfire intensity and weather conditions. Verify that pollution is due to wildfire smoke via ground reports (such as "it smells like smoke"), by checking the Fire and Smoke Map or by using the USFS modeling tool BlueSky. CALFire also posts updates on active incidents. 

AQI Index 

Clarity Sensors:  UC data viewable at

As part of a pilot project to evaluate local conditions, multiple PM2.5 sensors have been installed on campus. Outdoor concentrations are reported using the EPA NowCast algorithm for PM2.5 and may be co-displayed with nearby AirNow data on the same map/plot.

In response to indoor air quality concerns, EH&S may also be able to conduct a survey using a portable monitor. Contact (310) 825-5689 or report an indoor air quality concern at

Open Map Clarity Capture

Reference Monitors:  Maintained by California Air Resources Board or Local Air District, access via 

Current Air Quality Index (AQI) is used by the U.S. Environmental Protection Agency to report air quality on a real-time basis. Current AQI referred to as the “NowCast,” is reported for fine particulate matter of diameter 2.5 microns or less (PM2.5), the primary air pollutant of health concern during regional wildfire smoke events. To view, visit or SCAQMD (Northwest Coastal LA County). Also, download the EPA's AirNow app or sign up to receive alerts via EnviroFlash.

Note: The online AQI Calculator may be used to convert PM2.5 concentration in ug/m3 to AQI

AirNow Air Quality Capture --Los Angeles, CA


AQI Capture -- Westwood, CA


PM 2.5 Sensors:  Valuable for Spatial Trends and Indoor/Outdoor Comparison 

Low-cost sensors that count particles in air provide supplemental environmental data. It is important to recognize that these sensors are not maintained and calibrated like reference monitors, and may be less accurate than reference monitors. However, campus leadership will rely on our local sensor network to make decisions due to the absence of nearby reference monitors. These sensors are also extremely valuable to view spatial trends over a region or community.

Sensor data will be monitored by UCLA Environment, Health & Safety during wildfire events. The aggregate sensor data used for campus decision making will be updated on this site after a sustained AQI of 151 for one hour.

Note: PM2.5 concentrations may report high during wildfire events, due to the composition of wildfire smoke containing particulates that are of a lower density than dust. Also, one-minute or 10-minute readings will fluctuate more than results averaged over longer time periods like the EPA's NowCast algorithm.