What the song is about
Withers was explicit about the source. The song came out of watching Days of Wine and Roses, Blake Edwards' 1962 film in which Jack Lemmon and Lee Remick play a married couple destroyed by drink. What struck him was not the tragedy but the pattern:
They were both alcoholics who were alternately weak and strong. It's like going back for seconds on rat poison. Sometimes you miss things that weren't particularly good for you. It's just something that crossed my mind from watching that movie, and probably something else that happened in my life that I'm not aware of.
That last clause is the honest part, and it is why the song does not play as a film review. Withers took a structure he recognised on screen and let whatever was underneath it in his own life supply the feeling.
Read with that in mind, the lyric stops being a simple absence song. The narrator is not confused about what is happening. He knows she is gone, knows she will be back, knows she should not be, and knows he will take her back anyway. The line about it being warm outside whenever she is away is the whole argument in miniature: the world is fine, and he is not, and the difference is entirely his own doing.
The 26 repeats of "I know"
The most famous passage in the song is an unfinished draft.
Withers had intended to write actual lyrics for the bridge. What is on the record instead is the phrase "I know" repeated twenty-six times, which he had put down as a placeholder while he worked out what to say. The other musicians in the room told him to leave it. His account of why he agreed is characteristically unromantic: "I was this factory worker puttering around. So when they said to leave it like that, I left it."
It was the right call, and not by luck. A written-out bridge would have explained the feeling; the repetition enacts it. Someone saying "I know" twenty-six times is not informing anyone of anything — they are talking themselves round in a circle, which is exactly the behaviour the rest of the song describes. A first draft turned out to be truer than the finished version would have been.
Who is actually playing
The credits are better than the record's plainness suggests. It was produced by Booker T. Jones, of Booker T. & the M.G.'s, who also arranged the strings. The rhythm section is Donald "Duck" Dunn on bass and Al Jackson Jr. on drums — Jones's own bandmates, and the engine room of most of Stax's greatest records. The guitar is Stephen Stills, of Buffalo Springfield and Crosby, Stills & Nash.
It was recorded in Los Angeles, with overdubs added in Memphis by the track's engineer, Terry Manning.
So a first-time singer with no track record was handed the Stax rhythm section and a member of one of the biggest rock groups in America. The restraint of the result is the point: nobody on that list plays anything showy. The arrangement is a guitar figure, a bass part that barely moves, and strings that arrive late and leave early.
The B-side that took over
"Ain't No Sunshine" was not the single. It was the B-side of "Harlem", and it became a hit because disc jockeys flipped the record over and played the other side instead.
Withers was thirty-one and working in a factory making lavatories for Boeing 747s while all this happened. When the record went gold, his label marked the occasion by presenting him with a golden toilet seat — which is a joke about where he had come from, and also a fairly precise account of how abruptly his life changed. It was the first of three gold records he earned in the United States.
"Harlem", the intended A-side, was not wasted: the 5th Dimension later covered it, put it on their Soul and Inspiration album, and released it as a single.
Where to watch it
There is no music video. The song predates the form by roughly a decade, and nothing was filmed to promote it in 1971.
What exists instead are performances. Withers played it on the BBC's The Old Grey Whistle Test, and that 1972 performance is on his official channel alongside a 1974 BBC In Concert appearance. Below is the official audio of the studio recording — the version everything else is measured against.
The official audio of the 1971 studio recording. The 1972 Old Grey Whistle Test performance is on the same channel.
What happened next
The single reached number three on the Billboard Hot 100 and number six on the R&B chart, and Billboard ranked it the 23rd biggest single of 1971. It won the Grammy for Best R&B Song in 1972 and sits at 285 on Rolling Stone's 500 Greatest Songs of All Time.
It has never really stopped moving. Michael Jackson recorded it for his first solo album; it returned to the UK top forty in 2009 after Kris Allen sang it on the eighth season of American Idol, reaching number eight; and it charted again in 2020, going top ten in Scotland in the weeks after Withers' death. In 2024 the Library of Congress added the single to the National Recording Registry as "culturally, historically, and/or aesthetically significant".
One small measure of how literally people take the title: during the solar eclipse of 12 August 2026, Spotify recorded a three per cent worldwide increase in plays of the song.