Approximately 92% (or 99%) of USHCN surface temperature data consists of estimated values | Watts Up With That?
"An analysis of the U.S. Historical Climatological Network (USHCN) shows that only about 8%-1% (depending on the stage of processing) of the data survives in the climate record as unaltered/estimated data."
Temperature data are calculated from “adjusted” numbers, and are consistently changed to make the past look cooler and the present warmer so that more billions of dollars will flow to people who perpetuate this climate change fraud.
There is no convincing the climate change true believers, however.