Thursday, November 20, 2025

Nine day running mean (temperatures).

 A running mean for temperatures shows up or down trends filtering out extreme high or low values.

My EXCELL spreadsheet shows that trend as follows: I use a nine-day set of values. Current day, previous four days and next four days. So, a look back and a look ahead to see a nine-day trend.

Through November this trend continues to fall until we reach temperatures above and below about thirty to thirty-four degrees. Then in late February and March the trend reverses as winter fades.