April showers may bring May flowers, but what does the last weekend of May traditionally bring? Money, at least for Southern California theme parks, which open their summer season this weekend with more than a dozen new rides, attractions, shows, exhibits and parades.

Extended summer hours kick in at sunset Friday, and all of the region's water parks unlock their turnstiles Saturday for what industry experts say will be a record-setting summer for the nation's nearly 600 amusement, animal and water parks.

"We're looking for a solid growth year for U.S. parks and attractions," said Beth Robertson, spokeswoman for the International Association of Amusement Parks and Attractions, a trade organization in Alexandria, Va.