Thank goodness, for when it does it has a detrimental impact on a rugby match.
The Highlanders got home 17-10 over the Bulls in a damp and virtually empty Loftus Versfeld in Pretoria yesterday.
The heavens had opened before the game kicked off so the ground - which had no ability to soak up the water - had many puddles on it and the ball quickly resembled a cake of soap.
Now plenty of modern technology has come into the game but when the ground is that wet not even a group of Nasa scientists could make life easier for the players. So for the 80 minutes they slid and stumbled around the ground.
With most teams flouting the offside line in seemingly every game this season, players just do not have the time to move the wet ball quickly and efficiently.
That leads to a real arm-wrestle where the game's destiny comes down to one bit of magic or one huge mistake.
For the Highlanders the magician was centre Malakai Fekitoa, while the villain for the Bulls was lock RG Snyman.
With the game locked up 10-10 late in the second half, the home team got a roll on and replacement prop Pierre Schoeman went over under the posts.
But the try was immediately rubbed out after Snyman was deemed to have flown into a breakdown and used his shoulder illegally to clear Highlanders hooker Greg Pleasants-Tate out of the road.
Snyman was shown the red card and that left both sides down to 14 men. Highlanders winger Waisake Naholo had been red-carded with about 15 minutes left for a shoulder charge on Bulls midfielder Burger Odendaal.
It was a marginal call but players these days can simply not flirt with any foul play.
Naholo's blushes, though, were saved by the deeds of the man inside him, Fekitoa.
The big centre received the ball 40m out with five minutes to go. He spied a gap and went on a storming run to score under the posts.
It was a nice bit of skill and dash from Fekitoa in a match of few highlights.
Fullback Matt Faddes scored the Highlanders' other try after 22 minutes of the first half when he ran on to a Richard Buckman chip kick and outpaced the cover defence.
Faddes could not control a Bulls kick early in the second half which led to his counterpart in the Bulls, Warrick Gelant, scoring.
The Highlanders best were No8 Gareth Evans, Fekitoa and returning hooker Ash Dixon while Buckman worked hard.