1999 Jeep Cherokee temperature gauge

Engine Cooling problem
1999 Jeep Cherokee Automatic 218000 miles

I drove at highway speeds for about two hours and then got stuck in traffic. All of a sudden the temperature gauge jumped and pinned all the way and the check gauge light turned on. I thought I was overheating but after a 10 - 30 seconds the gauge returned to normal which is about a quarter of the way on the dial. Was stuck in traffic for about an hour and this happened a dozen times. Car never overheated (never saw any steam and didn't stall) but not sure what the problem could be. Thanks for your help.