We are having our fourth October snowstorm in Boulder today, and yesterday afternoon never made it up to the freezing mark.
But on this date in 1950 it was 82 degrees in Boulder with 90-degree weather reported Colorado, Nebraska, Kansas, Missouri, Oklahoma, Texas, Arizona, and California. More than half of the US was over 80 degrees that day.
From 1932 to 1950, Halloween was a warm day in the US. But temperatures plummeted after that and never recovered.
Read more at Real Climate Science