Stuck in traffic 340 got up to 220

It's okay....until next time.
80*F, no traffic, & it's ok?
You want your cooling system to work on the hottest days, not lower temp days.

You mentioned using 50/50 coolant. I presume that means 50% water & 50% antifreeze. Pure water is one of the best conductors of heat for a liquid. When you add 'something' to it, it is contaminated & it's ability to transfer heat is reduced. Anti freeze is a poor heat conductor & the more AF you add to the water, the more you reduce the heat transfer ability of the water. The moral of the story is to use the lowest percentage of AF for the expected minimum temperatures in your area to stop the coolant from freezing in the block.
Use a good 6/7blade clutch fan & shroud to help with idle/low rpm cooling.