Historically, most of the 100 degree days in Fargo Moorhead have happened in July and August.
The last 100 degree temperature recorded in the month of June in Fargo Moorhead was back on June 17, 1995. That 100 degree day was part of an eight day stretch with temperatures at or above 90 degrees. From June 14-21, 1995, the high temperature varied from 90 to 100 degrees, with most of those days reaching the middle 90s. On six of those days, the low temperature never dropped below 70 degrees so most of the nights were uncomfortably warm as well, at least for those living without air conditioning.
Since records began in 1881, there have been only two other stretches with more consecutive 90 degree days. One of those was from a stretch of nine days from August 18-26, 1976, and the other was the infamous heat wave of 15 such days from July 4-18, 1936. The 1936 heat wave included triple digit high temperatures on nine of those 15 days.