TV Ratings: 'Under the Dome' Premiere Falls After Steady 'Big Brother'

'Rookie Blue' also drops in its return, as 'Boom!' debuts on Fox.
Cliff Lipson/CBS
'Big Brother'

Thursday night proved to be a pretty crowded one for the broadcast networks, with original episodes on all five.

CBS won the night in the key demo of adults 18-49 thanks to Big Brother, steady with Wednesday's premiere 2.0 rating among adults 18-49, but Under the Dome took a hit in its return. The drama, airing a two-hour episode on its new night, averaged a 1.3 rating in the key demo. That's off nearly a full point from last summer's opener (2.1 adults).

Initial projections from CBS have the episode rising to a 2.0 rating with adults 18-49 after a week's worth of DVR.

Elsewhere, Fox saw game show Boom! premiere to a 0.9 rating in the key demo. That series, like all other summer reality debuts, now has to be judged against ABC's exceptional opener for Celebrity Family Feud earlier this week. Wayward Pines (1.2 adults) wrapped the night even with the week before.

Dateline was steady with a season high 1.3 rating among adults 18-49 on NBC, while the recently renewed Aquarius (0.6 adults) was steady with last week. Hannibal (0.4 adults), which won't continue on NBC, was also steady.

The Astronaut Wives Club (0.7 adults) shed three-tenths of a point from its premiere on ABC, and Mistresses (0.7 adults) dropped two-tenths. Rookie Blue (0.6 adults) shed a half of a point from its 2014 premiere.

On the CW, Beauty and the Beast brought a 0.2 rating with adults 18-49.