The steel drums on the track are played by keyboardist Cian Ciaran and were added on the spur of the moment after the group saw them "lying around" Real World Studios during recording.

The band experimented with reggae and "dirgy rock" styles before Rhys wrote the lyrics and, because they were inspired by adverse weather conditions affecting Latin America, tried playing along to a preset calypso rhythm track which was on his keyboard.

[5][6][8][nb 1] The singer has stated that, although he does not think the band have "any right to make Latin-influenced" songs, they did not choose a calypso style for the track in a cynical attempt to "crack South America".

[10] The melody line plays twice after which Gruff Rhys begins singing the first verse alongside the güiro, guitar and steel drums which no longer have a flange effect.

After another chorus the song's extended "play-out" section begins at 2 minutes and 13 seconds with Rhys repeating the lines "Don't worry me, or hurry me, blow me far away to the Northern Lites" accompanied by harmony backing vocals.

[14] Cigarettes saw "Northern Lites" as indicative of the Super Furry Animals' "genius idiosyncrasy and elegantly eccentric class" and described the song as "somewhere between a Mexican cocktail bar, a '60s surf party, a Vegas lounge show and a really good acid trip".

[7] Cigarettes compared the vocal harmonies on the track to those of The Beach Boys and stated that the song has a "classic, Bacharach" quality" although he did criticise the indecipherable lyrics which he felt could prevent the record from "its deserved 23-week residence at Number One".

[17] Echoing the views of Johnny Cigarettes, Gay Dad likened the song to the work of Bacharach and Hal David and complained that they could not fully understand Rhys's lyrics, as his vocals were too low in the mix.

[17] Writing for Mojo, James McNair described "Northern Lites" as a mix of "Tijuana brass, steel drums, and itch-scratching Latin percussion" and claimed that the "great" song was "one of the most frothily inventive pop confections" since Super Furry Animals' 1998 track, "Ice Hockey Hair".

"[24][25][26] Marc Hogan of Pitchfork claimed that the single's b-sides, including the "shiny, distorted mid-tempo number" "This, That and the Other", pale beside "Northern Lites" and the other tracks on Guerilla although they "do manage to scratch the itch for more SFA".

[30] The video begins with a shot of Super Furry Animals' 'SFA' logo, which appears on the cover of "Northern Lites", displayed above the words "Public information service".

This shot fades to show a full-screen translucent, fluorescent blue, image of the "warrior", also from the single's cover, which moves from the centre to the bottom right before shrinking and remaining stationary in the top right for the duration of the video.

Footage from curling events are then shown until 2 minutes and 40 seconds when the video cuts to show a man in a grey suit dropping a handful of grass on a road.