On this day, dragons are said to “raise their heads” (or awaken) with the sound of rumbling thunder, a sign of the coming rains that will revitalize the earth. Around this time, the earth is bursting with life, grass and trees are beginning to sprout and farmers are getting ready to till the fields. 

The festival falls on March 2nd this year. In Haikou, a parade will be held from West Beach to Holiday Beach, beginning at 9 AM. 
This will be followed by a blessing ceremony at Holiday Beach Central Plaza at 10 AM, and a beach treasure hunt with over 500 prizes such as USB sticks, seashell art, hot springs tickets, and more. Attendance at the Dragon Head Raising Festival is open to everyone at no charge.
SOURCE: Visit Hainan