When is LEGOLAND California Water Park open? LEGOLAND California Water Park is now CLOSED for the season. For your convenience you can access a complete listing of our park hours HERE. Was this article helpful? Related articles Are there any restrictions on Swimwear at the Water Park? How will the park verify if visitors have been vaccinated? What is a Resort Hopper Ticket? Am I required to wear a mask? What Nightly Entertainment do you have?