More than 170 million are under heat alerts across the Central U.S., Midwest, Southeast, and East Coast, with some areas feeling temperatures as high as 115 degrees.
Alerts are in place for a large swathe of the country, stretching from the Dakotas, lower Wisconsin, Michigan, and New York down to northeast Texas, Louisiana, and Florida.
Extreme heat warnings — which are issued when hazardous heat conditions are expected or occurring and when locals should avoid outdoor activities — are in place for portions of Iowa, North Dakota, lower Illinois down to Mississippi, as well as the Carolinas and Georgia. Some of those extreme heat warnings, including in Arkansas, Tennessee, West Virginia, and Missouri, are in effect through Wednesday evening.
Major cities under heat alerts on Monday include Dallas, Oklahoma City, St. Louis, Chicago, Memphis, Atlanta, Tampa, Charleston, New York, Philadelphia, and Boston.
The majority of record highs on Monday are expected to occur across Florida and Georgia, where high temperatures combined with high humidity will result in heat index values of up to 115 degrees.
Tampa, Chicago, Atlanta, and New York will see temperatures in the high 90s throughout Wednesday, with max heat indexes between 99 and 110 degrees.
New York City will have cooling centers open Monday through Wednesday, including at libraries, community centers, and senior centers.
The heat continues after a sweltering weekend in some parts of the country. Tampa, Florida, hit 100 degrees for the first time on record — a difficult feat due to high humidity. Charlotte, North Carolina, hit 101 on Saturday and 102 on Sunday, marking a period of rare heat.
In Arizona, first responders rescued at least three hikers experiencing heat exhaustion on mountain trails in Scottsdale and Phoenix on Saturday.
Record warmth is once again possible across Florida, the Mid-Atlantic, and the Northeast on Tuesday. Cooler temperatures are expected to arrive for the Midwest, Great Lakes, and Northeast by Thursday, while the South and Florida will continue to experience hot temperatures throughout the week.
Meanwhile, storms, rain, and strong winds will also be a threat on Monday, with eight million people at risk for severe storms across the northern Plains and Upper Midwest.
Storms have already battered the eastern half of the country with heavy rain and flooding, knocking down trees and power lines over the past week.
Thunderstorms are forecast to develop late Monday over parts of eastern South Dakota and form into a derecho — a widespread, long-lived wind storm with a band of rapidly moving showers or thunderstorms, according to the National Weather Service.
It’ll then move east-southeast into southern Minnesota and northern Iowa. The possible derecho is expected to produce a few tornadoes, and instances of severe hail are also possible.
Wind gusts of 75 mph, with some isolated gusts exceeding 100 mph, are possible across portions of South Dakota and Minnesota.
The I-29 and I-90 corridors are particularly at risk for the damaging winds, which could cause major travel issues for semi-trucks and high-profile vehicles. Cities at risk include Minneapolis, Minnesota; Sioux Falls, Pierre, and Aberdeen, South Dakota; and Fargo, North Dakota.
Heavy rain will also be a threat, with three to four inches of rain possible in the heaviest thunderstorms.
Widespread significant flash flooding is not anticipated; however, if repeated storms impact the same areas, it could result in isolated instances of flooding.
Ruidoso, New Mexico, is once again under a Flood Watch, effective through tonight. Three people were killed in the mountain community in historic flooding earlier this month, after the area suffered devastating wildfires last year. Burn scar flooding will be a risk if thunderstorms set up near or over the flood-vulnerable area.
