Spring may begin technically in March and more or less by general acceptance in April, but nobody dares to celebrate it until May. The last person to tune up and sing ''In the spring time, the only pretty ring time . . .'' in April was nearly felled by a hailstone the size of a small frozen grapefruit, hurled by a 70 m.p.h. gale.
But once May arrives, celebration not only becomes possible but necessary.
The only question is: How to celebrate? How to set up the figurative old Maypole and maybe literally dance around it?
It is a sunny Saturday afternoon. In the middle of a suburban playground 10 miles outside of Boston antique cars sit in a circle, like the stones of Stonehenge, as if to mark by their shadows the coming of the summer solstice.
Somewhere along the first-base line a Model A Ford starts up with a fine, firm chug, like the voice of a robust grandfather. Then, over by the chain-link fence that serves as the left-field wall, a vintage yellow MG breaks into sporty song.
Last of all, like the baritone in a roundelay, a fire-truck red Mustang - hood raised, immaculate engine exposed - fires up with a roar that catches even the attention of the tennis players in the far corner of the playground. Three children clambering on the merry-go-round over by the Charles River's edge freeze in midair and stare. Only the joggers running through the woods on the pine-chips track at the east border of the playground look straight ahead, as if nothing in this world exists except the ground and their feet and some invisible finish line.
The atmosphere fills with a scent of gasoline, too faint, too pleasant to be called air pollution. There's enough fresh air for everybody for once, just as there was in the old days when these cars were built.
A gleaming automobile, body polished, engine tuned, is as much a sign of spring as crocuses. How they do glisten - these old chariots! All that ubiquitous chrome practically makes the sun blink.
Near the entrance to the playground a portable refreshment stand, newly painted barn-red, dispenses soft drinks and popcorn. As they stroll about, admiring yesterday's state-of-the-art, the owners of the cars and their friends sip and munch. A free hand here and there holds a souvenir balloon. Occasionally one escapes and floats away in the soft blue May air.
The more passive celebrants, in shorts and T-shirts with slogans, stretch out in little patches of what was (and will be again) outfield grass and soak up sun.
The more active celebrants, with spray cans and gauze cloth, rub at invisible spots on their mature but flawless machines - buffing the hint of a shadow from a door handle or a wheel spoke.
Who is the winner of winners in this contest of classics? Perhaps the unseen car in the back whose horn plays a spunky version of the Colonel Bogey March from ''The Bridge on the River Kwai.''
No celebration of spring, or anything else, goes undocumented these days. On all sides, cameras click. In the parking lot outside, a panel truck bears the lettering, ''The Video Review,'' promising professional video cassettes of weddings and all such occasions. As some Bert Parks of antique automobiles announces the car-of-cars, will the moment be officially recorded?
It is just as well not to find out. Rites of spring should be kept general and unfocused, like a kindergarten picnic - everybody celebrating for all they're worth without ever knowing quite why.