[a2-16v-list] Blinking temp light

[Brian Wilkeson]

When I start the car, after it runs for about 15-30 seconds, the red
temp light blinks.  It doesn't matter when the temp gauge reads.  If I
turn the car off, wait a few seconds, and start it, it doesn't happen.
This only seems to happen when the car sits overnight...or while I'm at
work.  Can this blinking (steady blink, about a blink per second) mean
anything else?
 
2.0 16v GLI.  I have the dash with the temp gauge at the top center.
 
TIA
Brian