We can change the past. Well, not really, but we can change how it looks. All month long we were chasing after that magical 69.9 degrees. It’s the average of high and low temperatures from the month of September during 1908. The warmest September ever on record. Suspecting that something was not right, the La Crosse National Weather Service spoke with the Minnesota Climatology Office, and it’s been determined it needs to change. When compared to other reporting locations from that year, the Rochester September data set from 1908 was determined to be too high. Supported more so by the fact that on December 1st it was reported to be 80 degrees!
How does that happen? Easily. Now days we have standardize conditions so that thermometers read the air temperature accurately. This includes placing the thermometer in a specialized shelter, away from the sun and with vents to allow for air flow. The thought is that the 1908 thermometer was in the sun and consistently read high because of it.
This should clear the way for us to claim the top spot, but we won’t. Some data previously missing from September of 1931 was found at the Climatology Office. With this new information, 1931’s average temp for September was calculated to be 66.9 degrees, and claims victory over 2015. So, even after all of that, we can still chant “We’re #2! We’re number #2!”
-Meteorologist Cindy Morgan