Temp Gauge swings toward high-side and back to norm with 3 sec

My temp gauge does not peg, it will swing rapidly to just about an 1/8" short of the high line of the normal scale. It then returns to where it was originally all within 3-5 seconds when moving 10-15 mph. I have noticed this 3x within 500 miles over the course of 2 years.

I have not noticed the fuel gauge changing during this time, but the the temp gauge has never pegged.