The reason why AP decided to hide the data prior to 1958 becomes immediately obvious. Hot records were far more common not only in the 1930s, but 1950s as well. We also see far fewer cold records since around 1990. It is that lack of cold records which has skewed the ratio of hot/cold, and not an increase in the hot ones.
According to Guy Walton: “You are getting more extremes. Your chances for getting more dangerous extremes are going up with time.”
In fact, the opposite is true. The number of extremes, hot and cold added together, have been getting fewer in recent years...Borenstein claims that we are seeing more and more “record breaking heat” and “more extremes”. The opposite is true. Hot records are less common than in the past, and cold records have become even rarer. As a result, we are seeing a reduction in extreme temperatures.