Temperature is officially measured at a height of 2 meters, or about 6 feet, above the ground. Temperatures much higher are less relevant to life living on the ground and temperatures lower to the ground can vary widely according to surface types. (Think about touching a metal car hood in the summer sun or bare-handing a metal pole in winter.)
What this means is that on some of these September mornings, frost is likely to form on some surfaces even when the official temperature is still above 32 degrees.
When we meteorologists say, “It’s 32 degrees in Fargo-Moorhead,” we are really talking a reading on an instrument two meters above the ground just off a runway at Hector International Airport. Likewise, “It’s 32 degrees in Detroit Lakes,” refers to a spot 2 meters above the ground off the runway at the Detroit Lakes Airport. Local conditions will vary, sometimes by a lot.