Those three words can set off groans among the younger set and raise anxious questions for many parents: Is there enough macaroni and yarn in the craft cupboards to occupy another soggy morning with stringing beads? Will last week's homemade puppets hold up for yet another afternoon theater behind the drapes?
But even as rain gauges fill to record highs throughout the United States this summer, many educators are encouraging parents to consider taking their children outdoors during rainstorms to learn to enjoy nature's showers rather than dread them.
''We've had plenty of rain this summer, but our programs have gone on as scheduled,'' says Martha Kane of the Catawba Science Center in Hickory, N.C. ''Mostly, we've been trying to show children that a gentle rainstorm is really beautiful in the woods. It's amazing to see how little creatures react to rain before and after a storm - how many birds and small mammals come out to bathe in puddles or to look for earthworms.''
As a teacher at the Hickory children's museum, with a master's degree in environmental education, Miss Kane takes preschool children on walks in the forest, rain or shine. ''Just last week we were out doing some ecology games, hiding little stuffed animals where they'd be best camouflaged,'' she recalls. ''All of a sudden it started to rain and some of the kids started to cry. But I told them to look up at the canopy of leaves over their heads. Pretty soon they quieted down, and we were talking about how plants need moisture and how rain is really good for all the animals in the woods, too.''
With preschoolers, Miss Kane finds that a lot of imagination goes a long way toward making a rainy day a memorable outing. Together, she and her young explorers imagine mice taking cover from showers under mushrooms and talk about how trees and leaves form ''magic umbrellas.''
Miss Kane encourages parents to join the museum's walks in the rain and tries to show them how they can teach their own children about nature, even when they may not feel confident of their ability. ''There's a lot parents can do without having to know the names of plants and trees,'' she explains. ''I tell parents to get a copy of Rachel Carson's 'A Sense of Wonder' (New York, Harper & Row), because that's the most beautiful book I know of for showing parents how to teach children about nature. It tells them how to develop the sense of wonder in children that's so important. It shows them how to say, 'Isn't that an interesting snake?' instead of running in the opposite direction.''
A gentle rainstorm in the woods can be a good opportunity to help children develop their senses of touch and hearing, Miss Kane adds. ''Parents can sit children down in the forest, have them close their eyes, and listen to and then try to imitate the animal sounds they hear. Or a parent could blindfold a child and lead him by the hand through the woods, stopping to touch certain trees, and then see if he could find those trees later just by the feel of their bark.''
Miss Kane says she has some friends who enjoy holing up in a cave on a mountain trail to watch the approach of thunderstorms. ''As long as you're protected from the lightning, a thunderstorm can be a good time to teach children concepts concerning electricity and meteorology,'' she adds.
Some places to avoid during a thunderstorm are on a golf course, in a boat, on top of a hill, at the beach, under an isolated tree, or near a wire fence, overhead wires, or towers. If you sense a thunderstorm coming, find shelter immediately and don't let yourself be the highest object in the area.
''The main thing for parents to do is to educate themselves,'' Miss Kane says.
One parent who enjoys taking his children on walks in the rain is Robert Finch, a writer and naturalist who is a year-round resident of Cape Cod. ''I get upset with weather forecasters who get gloomy the moment the sun goes behind the clouds,'' he says. ''Because one of the really great things to do on the cape is to take kids to the Outer Beach at the tail end of a northeaster (storm). We've had our own kids out there in August, bundled up in gloves and scarves, and they love it.''
Mr. Finch, the author of ''Common Ground: A Naturalist's Cape Cod'' (Boston, David Godine) and an occasional lecturer at the Cape Cod Museum of Natural History, says the second or third day of a storm is a grand time for finding deep sea organisms that don't ordinarily wash up on the beach. ''You can see sea cucumbers and bottom-dwelling benthic crabs on the beach, and if you walk along the bluffs you run into all kinds of ocean birds. They get blown into shore and held there until the wind begins to back off, and when it does they all come streaming off the bluffs. It's fantastic!''
Mr. Finch has a number of favorite books for parents and children who find themselves with a rainy day to enjoy at the beach. A good primer, he says, is John Hay's ''Sandy Shore'' (Old Greenwich, Conn., Devin-Adair), and another fine beach guide is Dorothy Sterling's ''The Outer Lands: A Natural History Guide to Cape Cod, Martha's Vineyard, Nantucket, Block Island, & Long Island'' (New York, W. W. Norton).
''I don't consider myself a marine biologist by any means,'' Mr. Finch adds, ''but I do know enough to get kids outdoors to enjoy a good rainy day on the beach every now and then.''