It sounds like the position of weather stations is an issue.
I recall that when I lived in Chicago years ago, if a new record was set, the weatherman would frequently note that the official weather station was now at O’Hare, and that’s why a new official record was set because of the location of the weather station having changed.
If the official location of weather stations in many places has changed, that would account for a lot of the discrepancies we’re seeing.
The idea was that many traditional weather stations have become located in heat islands and giving false readings or in different conditions than they had in unaffected locations. The climate change alarmists agreed that was possible if not exactly so and agreed that new stations would be built away from urban centers and in locations not impacted by man-made structural influences, places like wilderness areas our far far out in the country. They would then compare the measurements of these newly located stations to historical records. It appears they forgot about that agreement.