Weather Talk: The frost free season is getting longer
One way to define and measure the length of the growing season for a location is to simply add the number of days from the last 32-degree temperature in spring to the first 32-degree temperature in the fall.
The average number of frost-free days in Fargo-Moorhead over the period of record going back to 1881 is 134 days. The average from 1881 through 1900 was just 120 days, but the average since 2000 is 150 days.
This season's frost-free period was 161 days, from April 30 through Oct. 8. Last year was only 141 days, from May 17 through Oct. 6. The shortest was 78 days in 1885 when it froze June 8 and again Aug. 25. The longest was 190 days in 2007 when the last spring frost was April 17 and the first in fall was Oct. 22.
The frost-free period has increased markedly since the 1880s. However, there remains a great deal of variability year-to-year.