Meteorological Fall starts on September 1. The average high for the month is 78.6 degrees in Dayton. The average low is 56.8 degrees.
The Miami Valley had a taste of the crip fall-like mornings with lows in the 50s on Sep. 2, 3, 6, 8, 9, and 10. Now on Sep. 13 high temperatures near 90 degrees.
It’s not uncommon to see 90 degree high temperatures during the month of September. The average last 90 degree high is Sep. 4. During the last decade that average was Sep. 13.
The latest average by decades comes between 1900 and 1909 where the average was Sep. 17. There isn’t a clear trend in the late September heat. Out of the last 10 years, only two years haven’t had a 90 degree temperature recorded in Sep. 2012 and 2020.
In 1934, 1958, 2000, and 2004 there was not a 90-degree temperature recorded in Dayton all year long.