During wildfire season, it’s important to monitor the AQI, or air quality index, frequently, as levels can change by the hour. You should start getting concerned when the AQI reaches above 100.

There are a growing number of options for monitoring air quality. One trend is toward neighborhood-level monitoring, made possible by crowdsourced data from private sensors. There can be discrepancies and glitches in all systems, but quality control is a big part of the effort.

Here are a few of the most popular options for checking air quality near you:
- Bay Area Air Quality Management District is the first regional air pollution control agency in the United States. It reports hour-by-hour air quality data.
- AirNow is run by the U.S. Environmental Protection Agency. Its fire and smoke map uses both government sensors and data from private sensors.
- PurpleAir is a technology company using its own private sensors that people can install at their homes, starting at around $200. In general, PurpleAir’s real-time air quality map provides more localized, more current, and less accurate readings than AirNow. Wood smoke particles, less dense than most PM 2.5 particles, can artificially elevate AQI readings, though PurpleAir has made strides to account for the issue.
- Clairity is a Berkeley-based company that offers relatively low-cost and easy-to-install wildfire smoke monitoring kits.
- IQ Air has an app called AirVisual, which was built by a Swiss air-quality company with its own sensor. The network taps into community participation by individuals or groups.
Each of the above options display AQI readings as a number and a color, most of which appear on maps updated dozens of times a day. The East Bay remains green for most of the year, meaning the concentration of pollutants is scored below 50. That means the air is safe outside.
When the AQI rises above 100, entering the orange stage, it triggers a Spare the Air alert, encouraging you to drive less and use combustible sources of fuel as little as possible. The BAAQMD, which issues those alerts, says particulate matter is the most common form of pollutant between November and February. It issued more alerts in 2020 than ever before.
REad more about air quality & other guidance in our wildfire guide
Oakland Wildfire Guide
Preparation advice, evacuation guidance and answers to your questions about air quality, power outages and defending your property.