The cycle of the seasons is not symmetrical, and it does not at all mirror the progression of the solstices and equinoxes.
The Vernal Equinox was Monday. The mean temperature (average of low and high) in Fargo Moorhead Monday is 30 degrees. At the time of the Summer Solstice, the mean temperature is 68 degrees, a difference of 38 degrees. At the Autumnal Equinox, the mean temperature falls just eleven degrees to 57. But by the time of the Winter Solstice, the mean temperature has fallen 35 degrees to twelve.
So the smallest difference is from the Summer Solstice to the Autumnal Equinox. The greatest difference is between the Autumnal Equinox and the Winter Solstice. Further, there is a difference of 25 days from the Winter Solstice to the average lowest mean temperature in mid-January. However, there is a 33-day lag time in summer from the Solstice to the average peak summer mean temperature around July 24-25.
