Gleichwie der Regen und Schnee vom Himmel fällt (Just as the rain and snow fall from heaven), BWV 18, is an early church cantata by Johann Sebastian Bach. He composed it in Weimar for the Sunday Sexagesimae, the second Sunday before Lent, likely by 1713.

The cantata is based on a text by Erdmann Neumeister published in 1711. While at Weimar Bach set at least one other cantata text by this librettist; he also set others by the court poet Salomon Franck. The text cites Isaiah, related to the gospel, the parable of the Sower. The third movement is in the style of a sermon, combined with a litany by Martin Luther. The closing chorale is the eighth stanza of Lazarus Spengler's hymn "Durch Adams Fall ist ganz verderbt".

The cantata falls relatively early in Bach's chronology of cantata compositions. It was possibly composed for performance on 24 February 1715, but more likely for a year or even two earlier. Sexagesima always falls within January or February, so the title's reference to snowfall would have been relevant to the weather at the time. Bach structured the work in five movements, a sinfonia, a recitative, a recitative with chorale, an aria and a closing chorale. He scored it for three vocal soloists, a four-part choir only in the chorale, and a Baroque instrumental ensemble which is unusual in having violas but no violins. The instruments originally specified were four violas, cello, bassoon and basso continuo. When he performed the work again as Thomaskantor in Leipzig, he added two recorders to double viola I and II an octave higher, thus creating a lighter sound overall.