The Christmas Day game between the Los Angeles Lakers and Boston Celtics averaged 5 million viewers, representing an 18% decline from last year's window. Despite the decline, it was the most watched game of the season thus far.
At least four out of the five games saw a decline from last year, with figures not available for the Warriors-Nuggets matchup.
The opening game between the Bucks and Knicks averaged 2.49 million viewers, down 39% from the Sixers-Knicks last year.
The Mavs-Suns game was down 42% with 1.47 million viewers, with the Sixers-Heat down 73% with 1.3 million viewers.
All three NFL games on Monday averaged more than 27 million viewers.