Letterman leaps to best rating in 18 months

After word leaked out that David Letterman had announced his retirement during the taping of Thursday night’s program, ratings for “The Late Show” jumped.

Thursday’s episode averaged a 3.2 household rating, according to Nielsen overnights, the program’s best performance in 18 months, since October 2012.

Letterman’s rating was up 28 percent over Wednesday night, when he posted a 2.5 in households.

The Letterman surge took a bite out of the usual late-night winner. NBC’s “Tonight Show Starring Jimmy Fallon” slid to a new low under Fallon, who began hosting the show in February.

He posted a 2.4 on Thursday, off 20 percent from the previous night and tying ABC’s “Jimmy Kimmel Live!” in households.

Kimmel, who tweeted a tribute to Letterman earlier in the day, didn’t appear to be affected by Letterman’s announcement. He matched his Wednesday night rating.

Letterman, who has hosted “Late Show” for 22 years and spent 11 years as host of NBC’s “Late Night” before that, said that he will stop hosting the show sometime next year. No successor has been named for Letterman.

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