Someone was claiming last night that the high frequency of 100 degree readings during the 1930s was due to TOBS double counting. While I find it difficult to believe that anyone could be stupid and irresponsible enough to reset a Min/Max thermometer at the heat of the day, and then leave it until the next day – that isn’t the issue here.
I looked through the metadata for all of the stations in Wisconsin, and only found one which lists a morning time of observation for much of the 1930s. This should cause the temperatures to be recorded too low.
This what I found. They had quite a few 100 degree readings prior to 1960, and none since. Suppose they were double counting. What is two times zero? No matter how you look at, the 1930s was much hotter.
This is just my first shot across the lame TOBS excuse. I plan to generate lots more data.