Heat wave spreads across US. When will it end?

Cooler temperatures are within sight but likely not soon enough and cool enough for a large swath of the country hit with dangerously high temperatures for days as the largest heat wave of the summer failed to budge from South Dakota to Massachusetts.

The relief is expected to begin arriving Thursday in some regions of the country as a cold front drops south from Canada. But it is not soon enough for others. New York City, for instance, is bracing for another day of temperatures in the high 90s.

Cooler temperatures are likely to sweep through the Midwest and into the Mid-Atlantic and Northeast regions by Saturday. They might be accompanied by severe thunderstorms.

The largest heat wave of the summer has stagnated over large regions, bringing sizzling temperatures and little hope of relief without rain, a growing possibility for some hard-hit areas as the weekend approaches.

Most states in the U.S. had at least one region where the temperature hit 90 degrees Wednesday, according to the National Weather Service, though the worst heat was in the Midwest to Northeast. Humid air just made it all feel worse, with heat indexes in some places over 100.

It was hot enough to buckle highway pavement in several states. Firefighters in Indianapolis evacuated 300 people from a senior living community after a power outage knocked out the air conditioning. The state of Illinois opened cooling centers. The Environmental Protection Agency said the heat was contributing to air pollution in New England.

Officials are blaming hot weather for at least one death. A 78-year-old Alzheimer's patient died of heatexhaustion after wandering away from his northern Kentucky home Tuesday in temperatures that rose to 93 degrees.

1 | 2

Next