UPDATED: A surge of breaking news -- the Boston Marathon bombing, Oklahoma tornadoes, the Jodi Arias trial -- brings a new (distant) runner-up to Fox News Channel, but the cable networks end the first half of 2013 with a lackluster June.

Two quarters into its rebrand under Jeff Zucker, there's good news and bad news for CNN. Nielsen Media Research has the cable news network rising to top MSNBC for a rare second-place finish behind Fox News Channel during the second quarter, but CNN ended the first half of the year with June viewership dipping to a monthly low not seen in nearly a year.

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Reclaiming the runner-up slot from MSNBC for the first time since 2010, CNN's quarterly returns were up from the first quarter and up dramatically from last June's 21-year lows. In total viewership, the network was up year-over-year by equal measures in both total day and primetime, while its demo showing improved most in primetime. But after the major breaking news events -- the Boston Marathon bombing, Oklahoma tornadoes, the Jodi Arias trial -- had passed, June saw the network slip to its lowest viewership (total day and primetime) since last August, before Zucker took the helm.

And while some broadcasts have fared stronger than others -- Anderson Cooper's 10 p.m. block surged in the eleventh hour by devoting the show to coverage of the George Zimmerman trial -- one CNN primetime broadcast that hasn't been particularly fortunate is Piers Morgan Live. The Larry King heir, who kicked off the second quarter with a slight rebrand from Piers Morgan Tonight, saw his second-lowest-rated month since premiering in January 2011 despite the quarter tying his highest. June brought the series an average 121,000 viewers in the targeted demo, 42,000 shy of HLN's Dr. Drew On Call -- though the two broadcasts tied in total viewers.

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June was muddy across the board, with less breaking news and a glut of live sports taking eyeballs away from primetime. The month saw lows for other broadcasts -- The Rachel Maddow Show, Hannity, and The O'Reilly Factor among them -- but the typical rankings remained otherwise intact.

MSNBC delivered its worst quarterly primetime showing among total viewers and adults 25-54 since 2007. The cable network suffered dips as other networks benefited from the quarter's bigger news stories. MSNBC's primetime returns in total viewers (576,000) and the key demo (191,000) were at lows not seen since the fourth and second quarters of 2007, respectively. The network did manage to improve month-to-month from it lows in May, when it fell below perennial fourth-place newser HLN.

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Throughout CNN's usurping of MSNBC, cable news' top performer, FNC, improved in total viewership from the same quarter last year but saw dips proportionate to MSNBC's in the targeted demo. FNC's biggest gain, total day viewership, owes a debt to America Live With Megyn Kelly. The two-hour afternoon news program saw its second-best quarter to date.

In the mornings, CNN's New Day was the quarter's most notable new edition. The first big programming launch under Zucker, it's aired only two weeks and has started off down double digits in total viewers and the key demo from the time period's quarterly average.

Read the complete rankings, Q2 2013 versus Q2 2012, via Nielsen:

Total Day

FNC: 1,179,000 total viewers, up 12 percent (238,000 in 25-54, down 6 percent)

CNN: 475,000 total viewers, up 49 percent (161,000 in 25-54, up 69 percent)

MSNBC: 360,000 total viewers, down 9 percent (122,000 in 25-54, down 5 percent)

HLN: 390,000 total viewers, up 61 percent (141,000 in 25-54, up 48 percent)



Primetime

FNC: 1,889,000 total viewers, up 5 percent (317,000 in 25-54, down 11 percent)

CNN: 666,000 total viewers, up 49 percent (228,000 in 25-54, up 77 percent)

MSNBC: 576,000 total viewers, down 16 percent (191,000 in 25-54, down 12 percent)

HLN: 518,000 total viewers, up 49 percent (178,000 in 25-54, up 51 percent)