Map: Wildfire smoke readings in Lake Tahoe and across California

Wildfires are causing air quality in the “unhealthy” category in some areas of California.

The map above, from AirNow, uses the official U.S. Air Quality Index, with color coding to designate the range of air pollution hazards. It measures ozone and particulate matter.

A number above 150 — in the red, purple or brown categories — is considered unhealthy for all people.

The highest readings on Friday, Aug. 9, were in the areas of the Park and Crozier wildfires. Crozier, in El Dorado County, is sending smoke into the Lake Tahoe basin; readings of 180 were recorded there on Thursday.