Contrary to the nonsense being spouted by the experts, Illinois temperatures have been getting cooler since 1930, with many fewer record temperatures.
I changed the algorithm for counting records, so that duplicates get double counted. For example, if an all-time record was set for a given day of year in 1936, 1953 and 1956 – all three years will get credit. This removes any bias from the count.
1936, 1934 and 1930 were the top three years for setting record maximums.
Record minimums are more evenly distributed, with 1917 being the year with the most record lows. 1930 was a very extreme year, as it ranked in the top four for both record highs and record lows.
Recent years have been near the bottom for both record highs and record lows.