Here is the 1939 entry in RAF Kenley’s Operations Record Book 1 for the first wartime Christmas Day.
State of the weather
Mainly cloudy at first, with cloud between 5,000 and 6,000 ft. gradually lowering. Sky obscured by fog from midday onwards. Visibility moderate at first, fog developing from 0900 hours onwards. Very little wind all day.
The first Christmas Day of the war. Everyone’s thoughts naturally turned to the question of how many Christmas days would pass before the war finished. Weather was cheerless. A very successful Christmas dinner held by the airmen in the Institute and a full programme of dances and socials has been arranged to cover the period between now and New Year’s Day.
So, in spite of Hitler, we shall enjoy ourselves.