David Letterman California Dreaming ... North Pole on His Face

11/16/2015 6:09 AM PST

David Letterman's face says he's ready for Christmas, but his head's still dreaming of warmer days.

Yes, Dave had his retirement beard -- aka 'the full Santa Claus' -- as he arrived at his NYC apartment on Sunday. He was also sporting a knitted cap of the California state flag.

Golden bears and silver beards ... it works on him.