"I'm happy to be here," Bob Hope told a Wolf Trap audience that included people in black tie, picnickers on a wet lawn and Nancy Reagan seated with Kay Shouse, the founder and donor of Wolf Trap. "I know you arranged this weather for me, didn't you?"

Last night may have been one of the wettest and coolest of Wolf Trap benefit galas, but the 10th annual event to raise money for the arts park was also one of the most successful.

That was largely due to the presence of Nancy Reagan, honorary chair of Wolf Trap. "I have a double reason for being here, other than enjoying myself," she explained, standing on stage next to Shouse. She said that fund-raising for White House restoration had so exceeded expectations that the private fund had been closed to further donations. But when Consolidated Aircraft wanted to make a contribution, "We decided it should go to Wolf Trap. So it gives me great pleasure to give Mrs. Shouse a happy birthday present of $25,000."

Shouse, will be 85 next week, thanked Mrs. Reagan, predicted that the gala would raise about $300,000 and said, "She isn't just our honorary chairman of our board. She's an active member."

During the performance, she and Shouse sat with Vice President and Mrs. Bush in Shouse's box. The president stayed home for the evening. And during an intermission, the stars milled around waiting for Nancy Reagan to come backstage. Zev Bufman, chairman of the gala and producer of the current Broadway hit "The Little Foxes," rallied them together like a coach getting his team ready. Reagan came through smiling, in turquoise blue chiffon with a brocade jacket, shook hands with each of them, and then they srunched together for a group picture.

"She said I was the best actor since Ronald Reagan -- do you believe that?" joked Ian McKellen, star of the play "Amadeus." "No, she said it was nice to be here. I asked her if she was cold. She said she was a bit."

Even amid the festivities, the rain remained one of the top topics. It had been so wet that Wolf Trap officials canceled the cocktails and dinner party that were to have opend the gala. But then they decided to go ahead with the dinner after all. So those who were game enough came to dinner in the rain -- between 200 and 300 people. Striped golf umbrellas were the order of the evening along with a menu that included chicken cacciatore, salmon with sauce Louise, rice, zucchini and white chocolate mousse.

"We heard on WMAL coming back home from Rehoboth Beach that the gala was off," said Sonny Orme of Leesburg, holding an umbrella in one hand and a Scotch in the other. "Then we heard from someone that if we got here fast enough we could have dinner." He and his friends sat calmly on picnic benches in formal dress.

"I think back to World War II and the monsoons in Burma and India," said a tuxedoed Clark MacGregor, the former congressman and Nixon administration member who is now working with United Technologies. "This is a piece of cake."

"It's not too great, frankly," said Kip Potts, sitting on a picnic bench and putting on her lipstick, the hem of her formal dress soaked with rain. "But it's not the worst thing that ever happened. It's for a good cause. And our next-door neighbor is Ed Crosland."

Crosland is chairman of the board of the Wolf Trap Foundation. He and his wife, Peggy, arrived right before the gala performance began, not realizing the dinner had been put back on the agenda. "When did that happen?" rasked Crosland. "We heard it was canceled, but then we got here and people said 'Oh, look at all those tables and food.'"

"How can they do that?" asked Peggy Crosland. "First it's off, and then it's on."

As master of ceremonies, Hope tried to keep everyone's mind off the rain. "I was hoping the president would come out," said Hope. "But he's recuperating. He's economizing on his health . . . and we all need him now." He paused from the applause and then started with the jokes.

"It's great having an actor in the White House," said Hope. "We went from peanuts to popcorn . . . It's the greatest thing to happen to Hollywood since George Burns played God.

"He got a lot of gifts in the hospital. Amy Carter sent him a book on nuclear proliferation. Prince Charles sent him a book on horsemanship."

Hope had a little to say on politics: "You all know about Jerry Falwell.

He's trying to put sex back into Congress where it belongs." And a little on Congress and sex: "It's nice to know the congressmen are doing it with someone else -- not just us." That got resounding applause. And a little on following rock groups at performance halls: "Funny, you walk into the dressing room, you take one breath and you can play the drums . . . Have you seen those rock concerts? Kids are smoking their programs. The cops are real cool. By intermission they're smoking their nightsticks."

On California: "On Sunset Boulevard, they think the space shuttle is the regular bus."

Other stars of the gala included Broadway actors Christine Andreas, Martin Vidnovic and Judy Kaye.At least one local political hopeful showed up -- Marshall Coleman, who made it to the dinner.

Coleman wants to be governor of Virginia. "Do you live in Virginia? Are you old enough to vote?" he jokingly asked someone to whom he was introduced. He claimed he didn't campaign during dinner. "I just ate," he said.

Some people felt they should get refunds for the hundreds of dollars they put up for tickets for the gala, which also starred opera singer Roberta Peters, Spanish singer Julio Iglesias and others. But Larisa Wanserski of the press office at Wolf Trap said she didn't know if they would get refunds.

However, most people remained good-natured despite the bad weather. "I think mud is inevitable," sighed one woman looking down at her shoes as she walked across the lawn.