Business was brisk at Teddy's Cocina in Pasadena as wildfire evacuees ate lunch and passersby ducked indoors to escape from the brown, smoky air blanketing the city.

AirNow is a collaborative effort of federal agencies that provides air quality data across the U.S. The site also has up-to-date information about the wildfires, resources, data, and interactive maps to help users learn more about particular areas and how they might be affected. There's also a free AirNow mobile app.

Air quality across parts of California is deteriorating to hazardous levels as strong winds drive rapid wildfire spread and stir up heavy dust.