I have a 1991 honda accord LX, with 128,300 miles on it and when ever i stop at a stop light for about 30 seconds to a minute, my radiator gauge seems to go above the halfway mark. it doesnt get any hotter until i go then my gauge goes down back to normal. i replaced my thermostat, about 6 months ago. maybe my raiator is just going bad, i dont know. if anyone could help that would be great.

 

It's possible you've got a problem with the cooling fans. Reason?
While stopped, you've no air circulation thru the radiator. The cooling system has to rely on the fans to supply air flow as the system approaches overheating. Once you get going, air flow is re-established and the temp drops.
I would also check your coolant levels, you may have another leak starting.

P