NOAA claims that the area of the US with unusually hot summer afternoon temperatures has increased in the US over the past 50 years to record levels.
The National Climate Assessment shows that summers used to be much hotter, and that peak temperatures are way down over most of the country.
There are no metrics which support the NOAA graph.
So how did NOAA create the fake data? They simply made it up. Almost half of all data from NOAA now is completely fake, with no underlying thermometer data.