As wildfire smoke from Canada continued to drift across the United States, creating unhealthy air quality, many places across the country were under air quality alerts on Thursday.
Heeding those alerts is important to staying safe, but monitoring air quality levels can also help you decide when it is safe to go outside. (Air quality levels can shift through the day, depending on the time and how much smoke is in an area.)
These apps can help you track air quality levels.
The AirNow Mobile App, available on iPhones and Android phones, was created by the United States Environmental Protection Agency, which oversees air quality across the country.
The app allows users to enter their ZIP code or city to get the most up-to-date information about air quality levels. The app also has a fire and smoke map that allows users to see where the thickest layers of smoke have drifted.