CBS is spreading its original summer fare across the week’s schedule, on Thursday announcing premiere dates for its warm-weather programming slate highlighted by three original scripted dramas and the return of reality veteran “Big Brother.”

“Under the Dome,” which was a breakout hit for CBS when it premiered in the summer of 2013, is moving from Monday to Thursday as it kicks off its season June 25. The net said on Thursday that Marg Helgenberger will guest star in this season’s “Dome” in an extended story arc this season that begins with the first episode.

The small-town drama based on Stephen King’s bestselling novel will launch its third season with a two-hour episode (9-11 p.m.), airing behind the second part of the two-night “Big Brother” season premiere.

“Big Brother,” which bows with an hourlong episode on June 24, will once again air Wednesday and Sunday at 8 and Thursday at 9. On Thursday, it will be preceded by encores of “The Big Bang Theory” and “The Odd Couple” and followed by “Under the Dome” in its regular timeslot.

CBS is using repeats of two of its biggest dramas, “NCIS” and “Criminal Minds,” to serve as lead-ins for new drama “Zoo” and second-year drama “Extant” on Tuesday and Wednesday, respectively. “Extant” also aired Wednesday at 10 last year.

In “Zoo,” based on the No. 1 bestselling novel by James Patterson, a wave of violent animal attacks against humans begin taking place across the globe. As the assaults become more cunning, coordinated and ferocious, a young renegade biologist (James Wolk) is thrust into the race to unlock the pandemic’s mystery before there’s no place left for people to hide.

Kristen Connolly, Billy Burke, Nonso Anozie and Nora Arnezeder also star. Jeff Pinkner, Josh Appelbaum, Andre Nemec, Scott Rosenberg and Michael Katleman are executive producers, with James Mangold, Cathy Konrad, James Patterson, Bill Robinson, Leopoldo Gout and Steve Bowen. Brad Anderson is directing and also serves as an executive producer. “Zoo” is a CBS Television Studios production.

CBS will announce additional summer programming details at a later date, including timeslots for a pair of Thursday series, “Mom” and “Elementary,” that will be displaced for a few months. “NCIS: New Orleans,” currently airing Tuesdays at 9, will air on the night at 10 this summer following “Zoo.”

KEY CBS SUMMER DATES

Wednesday, June 24

8:00-9:00 PM BIG BROTHER (Season Premiere, Night 1)

9:00-10:00 PM CRIMINAL MINDS

10:00-11:00 PM CSI: CYBER

Thursday, June 25

8:00-9:00 PM BIG BROTHER (Season Premiere, Night 2)

9:00-11:00 PM UNDER THE DOME (Two-Hour Third Season Premiere)

Sunday, Effective June 28

7:00-8:00 PM 60 MINUTES

8:00-9:00 PM BIG BROTHER (Sunday Premiere)

Tuesday, Effective June 30

8:00-9:00 PM NCIS

9:00-10:00 PM ZOO (Series Premiere)

10:00-11:00 PM NCIS: NEW ORLEANS

Wednesday, Effective July 1

8:00-9:00 PM BIG BROTHER

9:00-10:00 PM CRIMINAL MINDS

10:00-11:00 PM EXTANT (Second Season Premiere)

Thursday, Effective July 2

8:00-8:30 PM THE BIG BANG THEORY

8:30-9:00 PM THE ODD COUPLE

9:00-10:00 PM BIG BROTHER (Regular Thursday Time Period Premiere)

10:00-11:00 PM UNDER THE DOME (Regular Thursday Time Period Premiere)