Extreme heat continues across southern U.S. as cooler Canadian air moves into Great Lakes

Much of the southern United States remains gripped by a prolonged stretch of extreme heat, with record-high temperatures and unusually warm overnight lows expected across parts of the region.

The Southeast is at the centre of the heat through today, with temperatures expected to remain well above seasonal averages. Overnight lows could remain in the low 80s in some areas, providing little relief from the daytime heat when combined with oppressive humidity.

Record-breaking temperatures are also possible across the Desert Southwest and Southern Plains as a strong upper-level ridge builds over the Southwest.

Meanwhile, cooler Canadian air is expected to push farther into the Great Lakes region, bringing increasingly widespread showers heading into the weekend.

The contrast in temperatures will be particularly noticeable in the upper Midwest, where temperatures could fall into the 40s near the Canadian border while much of the southern U.S. continues to experience dangerous heat.

Extreme Heat Warnings are in effect across large portions of the Desert Southwest, southern Plains and Deep South. Heat Advisories are also in effect across Florida and much of the southeastern U.S. coast.