The average U.S. Web surfer watched 21.1 hours of online video content in October, watching a record 42.6 billion videos, comScore said Monday. Viewing of videos on Google's YouTube, Facebook, Vevo and other online video sites reached an all-time high October, according to the measurement firm.

Click here for a detailed view of comScore's results.

Internet video viewing increased signficantly compared to June, when comScore said the the average U.S. Web viewer watched 16.8 hours of video. 

YouTube and other sites owned by Google drew the largest audience, generating about 161 million unique viewers. Google was followed by Facebook, which reached 59.8 million unique viewers for its video content.

Music video site Vevo reached about 57 million unique viewers in October, while sites owned by Microsoft generated 49.1 million unique viewers. MTV.com, ComedyCentral.com and other sites owned by Viacom generated 48.2 million unique viewers. Comcast's NBCUniversal drew 39.3 million unique viewers, Hulu generated 29.2 million unique viewers and Turner Digital reached about 28 million unique viewers.

Read more: http://www.fiercecable.com/story/comscore-internet-video-viewing-hits-all-time-high/2011-11-28