What's the only place in this world who's fahrenheit and celsius degrees can be equal?

First, on a double scale thermometer, at -40 F which is the same than -40 °C.

Otherwise, any place where -40 is the actual temperature.

Antarctica? Siberia? There are lots of places where temperatures get to -40 C and lower (much lower).

Welcome to A2K visceral.

I'm completely gutted by your cunningly contrived question.

If there's only one place then it must be on the thermometer at minus 40.

Good...I succeeded then...and thank you!