Fast National ratings for Monday, October 31, 2011.
 
Whether you choose to attribute lower-than-normal viewership on Monday night to typical Halloween doldrums or to ongoing power outages on the East Coast, the bottom-line results were ultimately unchanged: ABC won the night overall, while CBS had no trouble winning among young viewers.
 
Whatever caused the viewership drop, FOX was particularly impacted with both "Terra Nova" and "House" slumping to season lows. The news was also bad for NBC's "Rock Center with Brian Williams," which tanked in its Monday premiere.
 
On to the numbers...
 
Among adults 18-49, CBS averaged a 3.8 rating, beating ABC's 2.7 rating in the key demographic. FOX was third with a 2.3 rating, while NBC averaged only a 1.2 rating for the night. The CW averaged a 0.3 rating on a repeat-filled night.
 
Overall, though, ABC averaged an estimated 13.9 million viewers in primetime to go with a 9.0 rating/14 share. CBS finished second with a 7.0/11 and 11.29 million viewers. There was a big drop to FOX's 4.0/6 and 6.46 million viewers and then to NBC's 2.7/4 and nearly 4.3 million viewers. The CW averaged 941,000 viewers and a 0.6/1.
 
[For the night, Univision averaged 3.04 million viewers and a 1.3 rating among adults 18-49.]
 
8 p.m. - Overall, ABC started primetime in first with "Scared Shrekless" (8.68 million viewers and a 1.7 key demo rating) and "Dancing with the Stars" (14.71 million and a 2.5 key demo rating). CBS was a close second overall and easily won the hour among adults 18-49 with "How I Met Your Mother" (10.7 million and a 4.1 key demo rating) and "2 Broke Girls" (11.14 million and a 4.2 key demo rating). FOX's "Terra Nova" drew a low 6.38 million viewers and a 2.1 key demo rating. NBC's "The Sing Off" averaged 4.88 million viewers and a 1.4 key demo rating. On The CW, a repeat of "Ringer" averaged just under 1.1 million viewers.
 
9 p.m. - "Dancing with the Stars" led the way for the 9 p.m. hour with 17.08 million viewers, finishing second with a 3.0 rating among adults 18-49. CBS was second with "Two and a Half Men" (13.81 million viewers and a 4.7 key demo rating), down after last week's temporary rise, and "Mike & Molly (11.53 million and a 3.8 key demo rating). FOX's "House" had its weakest night in recent memory with only 6.545 million viewers and a 2.5 key demo rating. NBC's "The Sing Off" slipped to 3.89 million viewers and a 1.3 key demo rating. On The CW, a second "Ringer" repeat averaged 867,000 viewers.
 
10 p.m. - "Castle" topped the 10 p.m. hour for ABC With 12.94 million viewers and also tied for tops in the 18-49 demographic with a 2.9 rating. CBS' "Hawaii Five-0" was second with 10.28 million viewers and also averaged a 2.9 key demo rating (though if you round up, CBS topped ABC in the demo). NBC's "Rock Center with Brian Williams" averaged only 4.13 million viewers and a 1.0 key demo rating.
 
All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.