That is a loaded question. On an 85 degree day, if idling for long periods of time, and say, 10-15 straight minutes of stop & go low speed traffic (in town), the water temperature could reach 225, possibly 230 degree's.
This is straight from the Yamaha Service Manual: (I converted from Celsius to Fahrenheit)
104 degrees Fahrenheit - 241 degrees Fahrenheit: Temperature is displayed. Go ahead with riding
243 degrees Fahrenheit - 282 degrees Fahrenheit: Temperature light flashes. Warning light comes on. Stop the motorcycle and allow it to idle until the coolant temperature goes down. If the temperature does not go down, stop the engine.
284 degrees Fahrenheit and above: Message “HI” flashes. Warning light comes on. Stop the engine and allow it to cool.
With this said, I do not idle my bike through town in stop & go traffic on a warm/hot day. I ride on rural, less traveled roads. I ride purely for sport. Many years ago, I road though town in slow moving traffic on an 85 plus degree day, and when I rolled up to my driveway, my water temp reached about 240-242 degrees.
For one, I don't have the desire to ride in 90 degree temps, because I wear full gear. When I do ride, I ride out in the open country, where my temps hover around 167-180 degrees. When I slow up, it will obviously go up to 200 degrees (in the warmer months). On a hot day, when riding down my street, coming back from riding, I'll see 222 degrees tops by the time I roll up back to my driveway. If I let it idle for a minute, I could see 224 degrees.
I don't ride in stop and go traffic because I don't want to melt my 21 year old lower fairing.
Hope this answers your question.
Tony