winter coolant temps

[Wolfsbrg8v at aol.com (Wolfsbrg8v@aol.com)]

Maybe a dumb ass question about normal coolant 
temperatures -- but this is the only scirocco I've ever
been around -- so:

In warm weather the temp gauge runs up to just above 
the midpoint, and then the fan kicks in.  But in colder 
weather (less than ~ 50 F.) the only time the coolant 
gets hot enough for the fan to engage is after a few 
minutes at stationary idle, stopped at a light or whatever.  
Back at speed, the temp gradually drops until the gauge 
reads steady at the ~ 1/3 point, with slight variation 
according to how fast the car is moving.  Obviously the
air thru the radiator at speed is keeping the temp down,
but is this normal, or is the thermostat stuck open?

TIA
Leo
late 84 "healing from a broken nose"