USHCN creates a non-existent warming trend in the US by tampering with data. The actual thermometer data (blue line) shows a cyclical warming and cooling on a 70 year cycle. But the data released to the public looks entirely different (red line below.) It appears to be warming, which is not what the thermometers show.
Final data
Raw data
They accomplish this using an impressive 1.5 degree data tampering hockey stick.

The steepest data tampering slope occurs since 1990, when they started making up huge amounts of data. Prior to 1990, they fabricated less than 10% of the data, but now they fabricate almost half of the data.

For example, all of the data this millennium at the Yuma Citrus Station, Az is fabricated.

These experts then go to the press and declare record temperatures, based on completely meaningless fake data which doesn’t even vaguely resemble the actual temperatures in their database.
The press has widely reported claims from Zeke that temperature trends are not adjusted upwards.