This fall is just the fifth time in Fargo-Moorhead since 1881 that there has not been a low temperature below 40 degrees into October. The latest into autumn without any temperatures in the 30s was in 1905, when the first time was Oct. 9. The other years were 1948 (Oct. 1), 1977 (Oct. 1), and 2013 (Oct. 7). In most years, the first morning in the 30s happens sometime in September, but it happens in August with enough regularity that it could be considered normal.
In Grand Forks, with records back to 1893, there have been just two autumns without 30-degree temperatures until October; Oct. 1 of 2019 and now this year. The absence of any chilly weather so far this fall should not be taken as a sign. Statistically, there is no good correspondence between a warm spell in the early fall and the temperature pattern during the following months.