Until I wrote about my search for good air in my Brooklyn apartment, I didn’t know there were air quality monitors. Now I can’t live without them. To know your indoor air quality index is to enter a realm where the invisible becomes something you can’t see.

We humans have evolved to respond to changes in temperature, precipitation, and wind. Bad air is quiet and mostly odorless, but long-term exposure to some vapors, particulates, and high levels of CO₂ can affect cognition and make us vulnerable to certain cancers, as well as heart and respiratory diseases. Reading the daily temperature and checking the weather forecast prepares us for the future, but checking your air quality may be the biggest step you can take to improve your health.

These air quality monitors were tested in two locations: a 130-plus-year-old Brooklyn apartment with a gas stove in a building undergoing construction, and a cabin in the woods in Maine that uses a electric stove. There were two cats, one dog, and two people throughout the trial period. I have different air purifiers running all the time. Neither location has central air or HVAC with MERV filters, nor do they have overheated exhaust fans to remove outside fumes. In both locations, it was cooking on the stovetop that produced the worst air. These monitors are used both on days with excellent outdoor air and days when the air quality is in the moderate zone, above 50 US Air Quality Index.

For more ways to monitor your air qualitysee our guides on Best Air Purifiers and Best Robot Vacuums.

Updated January 2025: We’ve added PurpleAir’s Zen Air, Govee’s Smart Air Quality Monitor, and the Ikea Vindstyrka; additional tables of specs; and updated links and prices.

Power up with unlimited access to WIRED. Get best-in-class reporting that’s too important to ignore $2.50 $1 per month for 1 year. Includes unlimited digital access and exclusive subscriber-only content. Subscribe Now.