Northeast, Midwest Heat Wave Could Smash Records | Weather.comGlobeUS°FArrow downPhone IconDownload AppUser anonymousSIGN UPUser AnonymousShareNortheast, Midwest Heat Wave Could Smash Dozens Of Records, Including New York, Philly, ChicagoWidespread 90s, even perhaps a few 100s, will bake much of the eastern two-thirds of the country in a dangerous heat wave. Here's when it will arrive and how long it could stick around. By•13 hours agoMillions Across U.S. Face Dangerous HeatA dangerous, widespread heat wave will bake the central and eastern U.S., bringing the hottest temperatures of the year and uncomfortably muggy air to the Midwest and Northeast that in some areas could last into much of this week.Already, daily record highs were set Thursday in Salt Lake City (104 degrees), their first triple-digit high of the year. On Saturday, Mitchell, South Dakota broke their daily high temperatures record at 104 degrees, smashing their previous record of 101. High temperature records were also set on Saturday across Minnesota and Wyoming, just to name a few.(MORE: )Weather in your inboxForecast LocationSign UpBy signing up you agree to the & . Unsubscribe at any time.Here are the main takeaways from the forecast:Heat Alerts- The National Weather Service has already issued extreme heat watches, warnings and heat advisories for large swaths of the central and eastern U.S., as you can see in the map below. Some cities in these alerts, including Omaha, the Twin Cities, Chicago, Kansas City, St. Louis, Detroit, Cincinnati, Pittsburgh, Philadelphia and New York City.- The highest level heat alerts are now called "extreme heat" watches and warnings. . These alerts indicate that heat illnesses are expected to spike when they are in effect. Minneapolis and Omaha are just two of the cities that are already expected to see dangerous conditions.(TRACK THE HEAT: | )Heat TimingHere's when we expect the worst of the heat:- Plains and upper Mississippi Valley: Finally seeing some relief on Monday- Rest of Mississippi Valley: Could last through much of this week- Rest of Midwest: Relief will arrive by Tuesday in the northern Great Lakes, but heat could last much of next week in the Ohio Valley- Northeast: Extreme heat on Monday, with some relief in New England, eastern Great Lakes by Wednesday. Mid-Atlantic and Appalachians heat could last much of next week(MAPS: )How Hot?- Highs in the 90s will spread over much of the country east of the Rockies, except for the far northern tier.- Dozens of locations, especially in the Northeast, will be within striking distance of daily record highs, especially through Tuesday.- A few locations could approach or top 100 degrees during the heat wave. , , and could flirt with the century mark during the peak of the heat wave this week. Some of those locations could do so multiple days during the heat wave.- New York's Central Park hasn't reached 100 degrees since July 18, 2012, according to the National Weather Service. Philadelphia hasn't reached 100 degrees in June since 1994. Boston's last 100-degree high was on July 24, 2022.(MORE: )Forecast Highs Next WeekHumid, Too- Oppressive humidity will accompany the heat wave.- This will particularly be the case in the mid-Mississippi and Ohio Valleys, but also into the upper Mississippi Valley, Great Lakes and at least parts of the mid-Atlantic and Northeast.- That means the heat index, or feels-like temperature, will be in the triple digits on one or more days for some cities in the Midwest and Northeast this weekend into early this week.- This also means that overnight temperatures will not cool off or provide any relief from the daily heat.(MORE: )Forecast Dew PointWhat You Should Do- , with hundreds of fatalities each year.- The combination of heat and humidity lingering into the night for several days in a row could be dangerous for those without access to air conditioning, especially in the cores of larger cities.- Check on family, friends, the elderly and those with chronic illness who live without access to air conditioning.- If possible, avoid being outdoors for long in the peak heat of the afternoon.- If not, take frequent breaks, avoid strenuous activity, drink more water than usual and wear loose, lightweight clothing.(MORE: )This map shows the National Weather Service Heat Risk forecast, an experimental index developed with the CDC to quantify potential impacts of excessive heat. The "extreme" level of impact is defined as "rare and/or long-duration extreme heat with little to no overnight relief that affects anyone without effective cooling and/or adequate hydration."Why So Hot?- This heat wave will be triggered by a change in the jet stream pattern.- Specifically, a strong bubble of high pressure aloft known as a heat dome will develop over the eastern U.S.- Sinking air near the center of this heat dome suppresses clouds, allowing the intense sunshine this time of year to heat the ground and air above it most efficiently.- Southerly and southwesterly winds will also tap hot and humid air from the South into the Midwest and Northeast.- This heat dome will only slowly weaken and "flatten out" in the East in the week ahead.The pattern triggering the heat wave features a "heat dome" of high pressure over the eastern U.S. Jonathan Erdman is a senior meteorologist at weather.com and has been covering national and international weather since 1996. Extreme and bizarre weather are his favorite topics. Reach out to him on , and .Connect With UsWe recognize our responsibility to use data and technology for good. We may use or share your data with our data vendors. Take control of your data.The Weather Channel is the world's most accurate forecaster according to ForecastWatch, , 2017-2022, commissioned by The Weather Company.Weather Channel© The Weather Company, LLC 2025, A multiday heat wave is bringing high temperatures and health risks from the Midwest to the Northeast, prompting warnings and emergency measures. See detailed maps about the latest heat index , Record-smashing daytime temperatures near 100 degrees are expected for millions from the Plains to the East Coast this week, while nighttime temperatures may stay above 80 in some metropolitan areas..