NCDC published the famous graph below, which has fooled millions of people into believing that 2012 was the hottest year ever in the US, and that the US is rapidly warming. Only problem is - NCDC’s own thermometer data shows that the US has been cooling, and that 2012 was second warmest after 1921.
The graph below shows the average of all of the daily min-max measured temperature data which NCDC uses. Note that the US has been cooling since 1895, and 2012 was slightly cooler than 1921.
The animation below switches between the measured data, and the published temperatures.
The way they created the fake warming trend was by warming the present, and massively cooling the past.
NCDC does not put any warnings or disclaimers on their graphs indicating that they are not showing the measured thermometer data, or that the data has been altered to turn a cooling trend into a warming trend.