The traditional overture to the Wimbledon tennis championships, always held on the preceding Sunday afternoon, is a garden party at the patrician Hurlingham Club, whose expansive lawns, playing fields and ornate clubhouse are nestled close by the Thames in London's fashionable Fulham section.

Here the well-heeled middle and upper-middle classes walk their well-heeled dogs, push their well-heeled children in prams (but not on the tea lawn), and watch a little social tennis amid the willow trees that weep into a pond populated by well-heeled ducks.

All the while, the Central Band of the Royal Air Force plays a lively medley of show tunes underneath a large maple tree that fronts the white-porticoed clubhouse.

Officially, this is the "Annual Reception of Overseas Lawn Tennis Players," given by the International Club.

In preprofessional days, it was considered good form for all the stars of Wimbledon to make an appearance, but few turn up these days. John McEnroe was the only player of stature seen today. He tried to practice on Hurlingham's well-heeled grass courts, but found the footing too slippery for safety. Then he stroked a few golf balls on the club's vast putting lawn, and took a taxis back to his hotel.

It was, in fact, an uneventful day at Hurlingham. Gloomy skies, a clammy chill and intermittent rain made the afternoon singularly unsuited for a Victorian garden party.

When the rain started, even the well-heeled Central Band of the Royal Air Force collectively left its battle station. Stiff upper lips are a British tradition, but not rain-soaked epaulets.

Few people took tea under the graceful maple grove that borders the bowling and croquet lawns. Instead, they congregated elbow to elbow at the bar inside at least until 5 o'clock, when the sun finally reappeared and the band reassembled, breaking into a rousing rendition of the "Colonel Bogey March."

By then, the fickle weather had dampened spirits and discouraged most tennis players who might have stopped by for a quick stroll or game at Hurlingham.

"When I ran this party, from 1927 until 1949, we never had a day of rain," remarked Ted Tinling, the noted coutrier and tennis man for all seasons. "Since I was sacked, there has been rain quite frequently. I feel quite pleased about that."

Tinling was sacked for dressing Gussie Moran in lace-trimmed panties, a much heralded breakthrough in tennis fashion. Unfortuately, the powers-that-be at Hurlingham did not consider such attire well-heeled, so Tinling was dismissed and the rains came. CAPTION: Illustration, no caption