John Wheeler: When the warmest part of the day is at night

FARGO — There are many obvious differences between weather in winter and summer. Perhaps less obvious to most people, but fascinating to those of us who watch weather closely, are the wintertime occurrences of non-standard diurnal temperatures. In other words, those occasions when the temperature rises overnight or it falls during the day.

This almost never happens in summer, but it is relatively common in winter. Because sunshine is relatively weak this time of year, daily temperature ranges caused by the sun are much smaller than in summer, often 10-15 degrees as opposed to 20-25 degrees in summer. Meanwhile, strong winter fronts often produce extreme changes in temperature which can easily overcome the relatively small day-to-night changes.



Over the course of a winter, we can expect a non-standard daily temperature pattern about once or twice a week on average..