President Obama’s State of the Union address on Tuesday night was watched by an average aud of 37.8 million viewers – making it the least-watched such event in 12 years.

The Nielsen estimates are a cume of the average audience watching the 14 broadcast and cable networks airing the SOTU live from 9 to roughly 10:20 p.m. ET. Individual network breakouts weren’t available on the broadcast side, as the telecasts did not include advertising and therefore will not be counted as part of the networks’ averages.

On the cable side, Fox News was the leader with 3.8 million, followed by MSNBC with 2.8 million and CNN with 2.7 million. FNC also led in adults 25-54 and held a sizable advantage over its rivals in post-address analysis.

President Obama has seen viewership for his State of the Union addresses decline each year after his initial one in 2009 drew 52.4 million; 48 million watched in 2010, and that number dropped to 42.8 million a year ago.

Tune-in for the SOTU is typically highest in a president’s first term. Over the last 30 years, the least watched addresses have been the lame-duck offerings by Bush in 2008 (37.5 million) and Clinton in 2000 (31.5 million).

The largest SOTU audience over the last 30 years was the 62.1 million who tuned in for President Bush’s address in 2003.