Temperatures in Eastern US Set to Drop Sharply

After weeks of relentless heat in the eastern US, a sharp and sudden cooldown is on the way—offering a rare taste of early summer chill, but bringing the threat of storms and renewed flooding along with it. A cold front, tagged along by high pressure from Canada, will sweep through the region later this week, dropping temperatures by as much as 20 degrees in cities that have been baking in the 90s. Chicago will barely break 80 degrees on Wednesday, while New York City, after sweltering near 100, will tumble to the low 70s by Friday—a temperature more typical of early June, CNN reports.

The cooldown, however, comes with a catch: a surge in rain and thunderstorms will accompany the drop, heightening the risk of flash flooding in areas already waterlogged from earlier deluges. Over 150 million people across the central US to the East Coast are currently under significant heat advisories, according to the National Weather Service, but attention will soon shift to flood watches, especially from the Midwest to the Northeast and the mid-Atlantic. New Jersey, New York City, Philadelphia, and Washington, DC are among the places facing elevated flood risk starting Thursday, with the threat moving into the Carolinas and Georgia by Friday.

Before the heatwave breaks, temperature records are expected to be tied or broken in some areas, especially Florida and the Northeast, USA Today reports. The National Weather Service said people should do everything they can to cool down until at least July 30. "Be sure to limit outdoor activity, stay hydrated, and ensure access to A/C or cooling centers," the service says. "Additionally, be sure to check on vulnerable family members, friends, and neighbors."