A haze is blanketing much of the Midwest as strong winds carry smoke from forest fires in Canada thousands of miles to the south.

National Weather Service forecasters say Tuesday that smoke from wildfires in northern Saskatchewan is blowing as far south as Tennessee. A thick band of smoke extends through much of North Dakota, South Dakota, Minnesota, eastern Nebraska, Iowa, Illinois and Missouri.

The smoke prompted health warnings in Iowa and Nebraska. The haze also has slightly cooled temperatures.

Bill Borghoff, a weather service forecaster in Chanhassen, Minnesota, says the smoky skies should remain through Wednesday but then shift to the east.

The haze could extend as far as New England later this week, but Borghoff says the smoke shouldn't be as thick as it travels east.