Apparently there is something that can pull viewers away from “American Idol:” Inauguration coverage.

The second week of Fox’s smash singing reality show saw viewership tumble last night, partly due to big tune-in for competing inauguration coverage from ABC and the cable news networks.

“Idol” averaged 22.4 million total viewers, according to Nielsen overnights, off 26 percent from the 30.1 million who watched last week’s season debut. “Idol” also slipped 23 percent among adults 18-49, to an 8.9 rating, though that was still easily the night’s top-rated show.

The 8 p.m. show was down 23 percent in total viewers and 24 percent in 18-49s compared to the same night last year.
 
Meanwhile, ABC’s inaugural ball coverage at 8 p.m. averaged a 3.5 18-49 rating and 12.6 million total viewers, roughly double the numbers it put up in the timeslot last week.

That undoubtedly pulled some viewers from “Idol,” as did the cable news coverage of President Barack Obama’s inauguration. Numbers for those shows won’t be out until much later today.

As a reminder, all ratings are based on live-plus-same-day DVR playback. Seven-day DVR data won’t be available for several weeks. Twenty-eight percent of Nielsen households have DVRs.
 
Fox was first for the night among 18-49s with a 6.8 average overnight rating and a 16 share. ABC and NBC tied for second at 3.4/8, with CBS fourth at 2.2/5, Univision fifth at 1.7/4 and CW sixth at 0.9/2.
 
At 8 p.m. Fox led with an 8.9 for “Idol,” followed by ABC with a 3.5 for “Neighborhood Ball: An Inauguration Celebration.” NBC was third with a 3.2 for “The Biggest Loser,” CBS fourth with a 2.3 for a repeat of “NCIS,” Univision fifth with a 1.9 for “Cuidado con el Angel” and CW sixth with a 1.1 for “90210.”
 
Fox and NBC tied for first at 9 p.m., each with a 4.7 rating, Fox for “Fringe” and NBC for more “Loser.” ABC was third with a 3.9 for the second half of “Neighborhood Ball,” Univision fourth with a 2.0 for “Fuego en la Sangre,” CBS fifth with a 1.8 for “Change and Challenge: The Inauguration of Barack Obama” and CW sixth with a 0.8 for “Privileged.”
 
At 10 p.m. ABC took the lead with a 2.9 for “A Moment in History: The Inauguration of Barack Obama,” with CBS second with a 2.6 for “The Mentalist.” NBC was third with a 2.2 for “Dateline” and Univision fourth with a 1.3 for “Aqui y Ahora.”
 
Among households, Fox was first for the night with a 9.6 average overnight rating and a 14 share. ABC was second at 7.3/11, CBS third at 6.1/9, NBC fourth at 5.5/8, Univision fifth at 2.2/3 and CW sixth at 1.4/2.