This picture, taken by www.surfacestations.org volunteer Don Kostuch is the Detroit Lakes, MN USHCN climate station of record. The Stevenson Screen is sinking into the swamp and the MMTS sensor is kept at a comfortable temperature thanks to the nearby A/C units.
The complete set of pictures is here
From NASA’s GISS, the plot makes it pretty easy to see there was no discernible multi-decadal temperature trend until the A/C units were installed. And it’s not hard to figure out when that was.
But hey, thy can “fix” the problem with math and adjustments to the temperature record.