An unbelievable heat wave will continue to unfold over the next 24 hours, with temperatures expected to climb to or above 100 in the Pacific Northwest and 100 in the Northeast. When humidity is factored in, it could feel an additional 10-20 degrees warmer than actual air temperatures in those regions.

Yesterday, Seattle-Tacoma International Airport hit 102 degrees at 4pm, breaking the previous June record of 96 set in 2017. It was one degree shy of the hottest day ever recorded at the airport, which was 103 in July 2009.

Seattle may become more hot yet: the National Weather Service in Seattle is calling for highs to rise to 107, although cautions temperatures could even go higher than that. The European ECMWF global computer model forecasts a  high of 94 for Seattle on Sunday and 107 for Monday while the American GFS computer model suggests 105 for Sunday and a shocking 119 for Monday. For yesterday’s high temperatures, the GFS did outperform the ECMWF, suggesting Monday’s forecast of 119 may be within the realm of possibilities. Even if both forecast models are averaged, Seattle is heading to record-breaking territory once again.

While central and western Washington and northern and central Oregon will see temperatures in the 100’s again, the same is true for portions of the northeast that usually don’t experience such extreme heat.

While temperatures will flirt with the 100 degree mark from time to time in places like Washington, DC, Philadelphia, and New York in the summer, similar high temperatures aren’t as common for places like northeastern Massachusetts, southern New Hampshire, and southern Maine. Temperatures will come close to or slightly exceed 100 in this region on Monday; when humidity is factored in, apparent temperatures will be well above 100 away from the immediate coast.

Due to the extreme heat, the National Weather Service has been busy issuing advisories ahead of the broiling-hot temperatures. Excessive Heat Warnings are in effect for all of Washington, most of Oregon, and portions of California, Nevada, Idaho, and Montana. Heat Advisories are also up for portions of Montana, Idaho, California, and Nevada. In the northeast, portions of Delaware, New Jersey, Pennsylvania, Massachusetts, Rhode Island, Connecticut, New York, and New Hampshire are also under Heat Advisories.