The coldest temperature recorded at the airport last month was a 40 degree low back on September 21. Since records began in 1881 there have been only three other Septembers without a low temperature in the 30s. Those other years were 1905, 1948 and 1977.
This is a minor correction from a post last week when I mentioned that in 1977 the first low below 40 was recorded on September 29, but it was actually on October 1 that year. The average number of days in September with a low below 40 degrees is seven such days. Even last year, which was one of the warmest years on record, September 2012 recorded 11 such days, including an earlier than average first frost on September 18. The record for the latest first sub 40 degree morning was on October 9, 1905.
It appears we will not be breaking that record this year considering the cold air that is expected in the coming days, but at a minimum we at least will finish in 2nd place.