“The ‘Dog Days of Summer’ are in full swing for most of the eastern two-thirds of the country as a strengthening heat dome over the Mississippi and Ohio Valleys gradually builds over the eastern US by the second half of the week. Temperatures soaring into the upper 90s will be high enough to set some localized daily records in the Southeast for late July. In addition, overnight/morning low temperatures dropping only into the mid to upper 70s will break a greater number of warm minimum temperature records. Heat indices from the Central Plains to the Southeast will range between 100-110F each day with localized readings potentially reaching 115F. HeatRisk depicts Major to locally Extreme levels across the Deep South and Lower Mississippi Valley today, with the Major levels footprint growing in size across the Midwest through Wednesday. Extreme Heat Warnings are in place for parts of the Central Plains and lower to mid-Mississippi Valley together with Extreme Heat Watches across the Midwest, including the majority of the Chicagoland area. Meanwhile, Heat Advisories encompass much of the Deep South and northern Florida. WPC continues to carry Key Messages for this ongoing heat wave” says an update from the National Weather Service.