In “Watermelon Sugar”, Harry Styles recalls a summer past, singing of scrumptious berries and a former love. The song was released without warning to fans, less than an hour before he performed the track during his hosting debut for Saturday Night Live.

The song is Styles' second 2019 release, following October single “Lights Up,” with both tracks featuring on his sophomore album Fine Line. It was first teased by Styles in a tweet posted on October 22, 2019, also referencing his 2017 track “Kiwi,” commenting:

Kiwi walked so Watermelon Sugar could run.

In March 2020 NPR Tiny Desk Concert Harry elaborated on what the track is about:

It’s kind of about that initial euphoria of when you start seeing someone, you start sleeping with someone or just being around someone and you have that excitement about them.

In March 2021, Harry received his first ever Grammy Award for “Best Pop Solo Performance” with this song.