It is currently 93 degrees in my neck of the woods, and we are being warned that with the heat index, daily temperatures could warm up to 110 degrees. We are under an "excessive heat warning" through Saturday evening.

If you live in the Central or Eastern US, chances are you are also under a dangerous heat wave warning.

AccuWeather estimates that more than 87 million Americans live in an area where a daily record-high temperature could be set on Saturday, and says more than 200 million in the eastern two-thirds of the nation will swelter in very hot and humid conditions into this weekend.

Here's what you need to know about this heat wave.

As of the time of this writing, the National Weather Service's latest update (which is valid through Sunday, July 21) stated the following:

…A dangerous heat wave is building in the central and eastern U.S…. …Severe weather and flash flooding are both possible for the Upper Midwest this evening… An upper-level ridge is building over the southeastern U.S., setting the stage for what will be a miserably hot and humid weekend for millions of Americans.

The sprawling area of high pressure will drive hot and humid air north and east from the Gulf through the Northeast. Daytime temperatures will soar into and through the 90s from the Plains eastward, and overnight minimums in the 70s and 80s will provide little relief. Heat Advisories, Excessive Heat Watches, and Excessive Heat Warnings are in effect for the Plains, Mississippi and Ohio Valleys, and the Eastern Seaboard.

Dozens of record high minimum temperatures are forecast to be set across the eastern U.S., and a handful of record high maximum temperatures will be challenged. The heatwave is expected to persist through the weekend across the east, but a cold front ushering in cooler air will march across the U.S. as an upper-level trough begins to build near Hudson Bay.