There is no water temperature sensor.
There is only a cylinder head temperature sensor.
The water is infered to be ~20% colder than the head temperature.

When ICE is off, cylinder head cools quickly... more so if cabin heat is on, which I think does not involve the thermostat.

The Ford thermostat is listed at 190'F.
The car never gets more than 191'F infered with ICE continuously on, which is based upon CHT of 233'F actually measured.
-John