Seasonal Variation in Daily Temperature Ranges

Abstract

Abrupt spring and autumnal changes in the daily temperature range, from low winter values to higher nonwinter values, were noted in the Minneapolis-St. Paul temperature record. Since this feature was even more evident in five rural and small town Minnesota stations, it can be accepted as real. The inverse relationship found between surface albedo and the daily temperature range indicated that the reduced winter temperature range is associated with snow cover. A second factor controlling the temperature range is cloud cover. This led to the conclusion that variation in net solar radiation is the primary factor. A strong statistical relationship between daily temperature range and the three variables considered (solar radiation, albedo, and cloud cover) was limited to the spring and fall. In March-April the statistically significant factors were solar radiation and albedo, while in October-November they were solar radiation and cloud cover. For the October-December period albedo was also statistically important.