Low temperatures this weekend were in the 40s and even upper 30s in some locations. The featured chart shows the frequency of experiencing a given threshold temperature by a certain date in the fall for Ames. While having a low temperature in the upper 40s by now is common, the 30s are a few weeks away.

Voting:
Good = 16
Bad = 3

Tags:   fall  

The featured chart is a temperature composite of the time period before and after the first sub 32 degree temperature in the fall from the Des Moines Airport. The three lines represent the temperature range and average of the observations 3 days before thru 1 day after the event. The 12 hours before the first event show a rapid cooling which is often the case with clear skies during the night time hours. Those clear skies are then typically around for the next day when temperatures quickly recover.

Voting:
Good = 23
Bad = 4

Tags:   fall   freeze