a 205 T-stat doesn't fully open until 210 or 215 degrees, so the engine will usually run a couple [?] degrees hotter sitting in traffic.
this is where a factory designed cooling fan/shroud assembly works very well keeping the temperature in check.
these days, i prefer a factory setup over any aftermarket item, although others have had success using what the aftermarket offers.
just my experience and opinion.
your mileage will vary.