If it does rain, the All England Club authorities need to be rather more imaginative about entertaining the crowd than they were earlier this week.
One answer, of course, is to send for Anne Widdecombe. Her skill in getting an equally rain-sodden and far more angry crowd on her side outside the passport office on Tuesday was a wonder to behold. There's not a lot to keep one busy in opposition at the moment, and Miss Widdecombe's latent music hall skills in winning over a hostile audience could never find a better home than Wimbledon.
This is because the show-court spectators at Wimbledon are largely drawn from Lawn Tennis Association ballots at individual tennis clubs. Such people will immediately recognise Miss Widdecombe as one of their own. Bossy, prim, uncontradictable and probably not a very good player, she is a born tennis club committee member, a catering secretary manque.
Chatting with Miss Widdecombe would pass the time during a shower. More prolonged periods of rain demand more desperate measures. Thus, Sir Cliff Richard was wheeled out in 1996 for a karaoke session with the Centre Court spectators, with Martina Navratilova at his shoulder joining in an impromptu version of "Congratulations".
It was the most unlikely duet since David Bowie crooned "Little Drummer Boy" with Bing Crosby. But the crowd seemed to like it. A sub-committee at the All England Club should prepare more pro-celebrity duets for future cloudbursts. I'd like to watch the restrained, consummately English Tim Henman shimmy with Tina Turner; the unpredictable, wild looking Venus Williams calm her pre-match nerves with Des O'Connor.
Or why not a group rendition by The Parents From Hell, not a bad name for an ageing rock band, actually. Dorkic pere snarling, Hingis mere sighing, and Mary Pierce's dad spitting out the lead vocals.
On Tuesday the Wimbledon authorities put on a jazz band to ease the waiting. But jazz is frankly more of a sunny summer evening's entertainment. Once it's raining, British tennis fans like nothing better than to wallow in it. Bob Dylan should be brought over to sing Desolation Row - the five set version.
Perhaps, though, there is no need for any extra curricular entertainment when rain interrupts play. Sports followers and sports commentators in Britain show most initiative when there's no sport to be seen. Test match commentaries hit new heights when rain stops play; a rapport develops with the viewers and listeners that never seems as intense during actual play. But then rain-interrupted cricket was the first example of interactive broadcasting. A mere tummy rumble from a commentator would spur a listener's culinary skills into action.
At Wimbledon novels are read, new friends are made, reputations destroyed. There is a perverse pleasure in eating strawberries in the rain, an elemental sense of victory over the gods. Our players may never win the tournament, but our spectators will not be beaten.
There is probably a breed of spectator for whom defying the elements is the noblest form of sporting endeavour; the happy few who spend the summer travelling without umbrella from Wimbledon to the Regent's Park Open-Air Theatre, from the Test Match to Shakespeare's Globe, ever hopeful the heavens will open to test their sporting endurance.
But if the All England Club really does feel duty-bound to lay on entertainment in the rain, then perhaps it can take a tip from the "tennis coverage" in the Daily Mail. Yesterday that newspaper devoted a page to Sue Barker's hairstyle.
The large screen on the concourse near the burger stalls and strawberry sellers has been showing too much tennis. When the rain comes it can switch to tennis fashion, as our newspapers do, to fill the spaces originally earmarked for sports coverage.
Imagine the scene in all its English tradition. On the screen by the outside courts photographs of the Barker barnet, past and present, provoke debate among the rain-soaked Pimm's drinkers and strawberry eaters. From nearby comes the distinctive sound of the latest Wimbledon pro-celebrity collaboration. The Prodigy are singing their hit "Smack My Bitch Up" with Virginia Wade. Somewhere a viewer is baking a cake for her favourite commentator. The summer of sport is here.