The sudden heat wave on Monday, June 1, remains the weather story of the week around here.
The sudden late-afternoon rise in temperature was the result of a meteorological process called "compressional heating." A cold front was forcing a pool of very dry air up against the warm and humid air in and around Fargo. Dry air, which is heavier than humid air, compressed the humid air, causing it to warm up by several additional degrees. Additional compression was caused by downward-moving air from an area of high pressure in the upper atmosphere.
The 97-degree temperature was the warmest since Oct. 10, 2015. That Sunday afternoon back in 2015 was also a compressional heating day, in which an autumn cold front compressed the heck out of an already warm lower atmosphere. When the cold front hit late that afternoon, wind gusted to 46 mph and the temperature fell to 37 degrees the next morning.