What you describe is normal - sitting still the engine will heat up since the air flow isn't circulating as much as when you're driving. At idle the fan isn't moving as fast as when you're driving.
For what it's worth, engines run a little more efficiently when hotter. If you'd said you were pushing 210 or 220 (my Healey will boil over at idle, that is a problem) then I'd worry.
It's not really a problem but the solution - if you need one - is to augment or replace the mechanical fan with an electric fan.
Fits snugly to the radiator, can be temperature controlled to come on whenever you want, and can even be placed between the radiator and the grill so it's practically invisible. Maybe $150 to $200 depending on the size.
(Or yank one out of the junkyard from an old Honda or something.......)
-Boyo
