Above: Wildfire smoke, at 7:22 a.m. MDT July 25, 2017.
(Originally published at 7:45 a.m. MDT July 25, 2017)
Smoke from wildfires is affecting most of Canada, the Great Lakes area, and the central and north-central United States.
The National Weather Service has issued Red Flag Warnings or Fire Weather Watches on Tuesday for areas in Montana, California, Oregon and Nebraska.
The map was current as of 7:40 a.m. MDT on Tuesday. Red Flag Warnings can change throughout the day as the National Weather Service offices around the country update and revise their forecasts.