[1][2] The song was written by the trio, alongside Iain James and George Moore, the latter of whom also produced the track.

In December 2022, the Sugababes announced the surprise release of their eighth studio album The Lost Tapes on social media, that consisted of previously unreleased material.

[13][14] On 14 September 2023, the day prior to the concert, the group announced on Instagram that their new single would be released at midnight, and they performed the song for the first time during the show that evening as part of the setlist.

[25][26] Writing for Clash magazine, Robin Murray described "When the Rain Comes" as a "new classic" that "[radiated] pop brilliance".

[3] After the group performed the song for the first time as part of their "one night only" concert, Retro Pop Magazine noted that the song was a "soulful mid tempo [track]" that was "worlds away from the hyper electro-pop that ultimately characterised the final chapter of the group back in 2011", added that the song [leaned] into the soundscape of their classic debut album One Touch (2000) and [conjured] a full-circle narrative reflecting on their path so far.