A "Heat Kills" sign at the Capitol Reef National Park outside of Torrey, Utah on June 14, 2022. Record-high temperatures continue to sear the U.S. Southwest through the Mississippi Valley. Photo: George Frey/Bloomberg via Getty Images
More than 100 million people are under heat warnings and advisories Wednesday, as an "extensive" heat wave is expected to bring above-normal to record-breaking temperatures in many places from Michigan to northern Florida, according to the National Weather Service (NWS).
The big picture: The heat wave is expected bring with it thunderstorms along its periphery, making "several tornadoes, large to very large hail, and damaging winds all appear likely" across parts of the Upper Midwest into Upper Michigan, according to the Storm Prediction Center.
- Heat warnings and advisories were issued for all of Indiana, Illinois, Ohio, Kentucky, most of Georgia and Alabama.
Why it matters: Excessive heat events are the leading weather-related killer in the U.S. Between 600 and 1,300 Americans die from excessive heat, according to estimates cited by the Environmental Protection Agency.
- They can significantly strain the power grid, leading to power interruptions and greatly increasing the risk of heat-related deaths as people lose access to air conditioning and water supplies are interrupted.
- Climate change from greenhouse gas emissions is causing heat waves to be more severe, frequent and longer-lasting.
By the numbers: Temperatures in parts of Georgia are expected to reach 111°F, while Atlanta may hit 107°F.
- Temperatures across parts of Alabama could rise to between 105°F and 109°F with possible severe storms appearing in the afternoon.
- Parts of Iowa, Illinois, Missouri, Indiana, Michigan and Ohio could also see temperatures from 100°F to 110°F.
- The NWS said that 32 locations across the Midwest and Southeast are expected to either break, tie or come within 1°F of their record high temperature on Wednesday,
An excessive heat warning was issued for much of southern Arizona, where several wildfires are raging, including two north of Flagstaff that forced the evacuation of around 2,500 homes on Monday.
- Flood warnings are also in place near Yellowstone National Park, where flash flooding this week caused significant damage and forced the park to close its entrances.
What's next: The NWS said some moderation should be expected for Thursday across the Upper Midwest, though temperatures across much of the region will likely remain above normal.
- In fact, the extreme heat is likely to shift back westward, and send temperatures soaring into the triple digits from the Plains to the Midwest and Central states over the weekend into next week.
Go deeper: Drought-hit Colorado River water supplies near "moment of reckoning"
Axios' Andrew Freedman contributed to this report.
Editor's note: This story has been updated to include the latest information on heat warnings and advisories.