omplete with traceable data. You can do it yourself.
Whether recording in the afternoon or Morning. The trend is the same. DOWN and DOWN
NOAA massively tampers with US temperature data, to turn a century of cooling into warming.
The two leading excuses for tampering with US temperature data are time of observation bias, and changing station composition.
The time of observation bias adjustment is based on the idea that most stations during the 1930s reset their min/max thermometers during the afternoon, causing some double counting of hot maximum temperatures. NOAA adjusts for this by cooling the past, and warming the present.
It is simple enough to test their theory out, by splitting the stations into two groups – 1930s morning stations, and 1930s afternoon stations. If the TOBS theory is valid, the morning stations (blue line below) would be warming faster than afternoon stations (red line below.) But as you can see, the slope of both lines is nearly identical – both are cooling at about the same rate. The morning stations are warmer, because they are located at lower latitudes where people are more likely to work outside earlier in the day, The average latitude of the morning stations is 38.5°N and the average latitude of the afternoon stations is 39.7°N.
