[2] Timed at 5 minutes and 50 seconds, September in the Rain is one of the shortest among all Warner Bros. Merrie Melodies or Looney Tunes animated short subjects.

Due to the controversy engendered by the sequences considered to depict racial stereotyping, it has been most commonly edited to a much shorter running of four or even three minutes, with the invariable excision of the Fats Waller–Louis Armstrong "Nagasaki" production number[3] and, often, the Al Jolson title song performance.

Then, a can marked "Searchlight", with a lighthouse pictured on the label, sends out a light beam, while four identical blonde women wearing blue dresses, aprons and wooden shoes, step off four cans of "Old Maid Cleanser" ("Old Dutch Cleanser") and perform a Klompendansen-styled clog dance which ends with the women showing their clothed backsides, including a flash of white underwear, to the audience.

It has drawn lines indicating eyes and eyebrows as well as a large mouth which inhales air and inflates the glove, emitting the sound of a bagpipe upon exhaling.

The camel executes a dancing walk to the bagpipe music which carries over to the next shelf, featuring two bottles of "Good Ol' Scotch", each of which bears a label depicting a kilt-wearing thistle, the floral emblem of Scotland.

The melody of "By a Waterfall" is heard (sung by unbilled Wini Shaw), as the water cascades to the shelf below and rains over round (unnamed) cardboard containers depicting an umbrella-holding girl resembling the familiar image from "Morton Salt".

Aunt Emma extends arms to him from her package and responds, with a big smile, "Sonny Boy", a song Jolson introduced in the 1928 Warners' part-talkie The Singing Fool.

The miniature stars step off the fronts of the packs, as spats-wearing Astaire flings away his top hat along with cane and, sporting ballroom dancing outfits, they launch into a realistically intricate rotoscoped performance in which, as a representation of their stairstep routine, they repeatedly dance up and down matchboxes, past oversize packs of "Park Avenue" and "Lucky Blows / They're Roasted" (Lucky Strike) cigarettes.

Watching Astaire and Rogers finish their dance, two nearly-naked figures, wearing only brief tutus on the box front of "Gold Rust Twins Washing Powder" (Gold Dust Twins), one of whom is a caricature of Fats Waller wearing a tiny bowler hat, shout, "swing it, brother", to a "Bisquit" (Bisquick) chef banging upon an oversized drum.

Fats Waller leans back in his piano chair and continues to play with great speed, now using his toes, while Louis Armstrong energetically picks up the "Nagasaki" melody on his jazz trumpet, with close-ups of his fingers pressing the valves.