People of all ages will brave the cold waters as they jump in the lake for Dunk for Harold.
The fundraising event for Life Education Trust Rotorua is next Sunday at Tikitapu (Blue Lake).
The purpose of Life Education Trust is to educate and empower children to make healthy choices, so they can live full and healthy lives.
Trust Rotorua chairwoman Jules McLaughlin said about 100 people usually took part.
A $2000 travel voucher will be up for grabs and for every $100 a participant raised for Life Education Rotorua they got an entry into the draw.
There were also many spot prizes such as hotel, restaurant and tourist attraction vouchers.
Ms McLaughlin said it was usually teachers and children who jumped in the lake and it would be great to have other community members join in.
"It's just a great fun event. Everyone dresses up in ridiculous outfits."
She said dunkers ranged in age from as young as 4 up to people in their 60s and 70s.
Westbrook School pupil Paige Dudson, 10, said she was looking forward to dressing up in a crazy costume and raising money for Harold because he was amazing,
Danielle Green, 10, said she had done Dunk for Harold in previous years and she enjoyed jumping in the lake with her friends.
Sierra Harris, 10, said it was fun seeing Westbrook School principal Colin Watkins jump into the lake.
Teacher aide Julie Voss enjoyed getting the children all rallied up and ready to go.
"Finding interesting ways to raise money for Harold and Life Education is always great."
Ms McLaughlin said they hoped to raise $20,000 from the event this year.
She said Life Education Rotorua saw every primary and intermediate school in the city, which was about 6000 children a year.
They were not government-funded.
For the links to enter the dunk or donate visit the Life Education Trust Rotorua Facebook page.
What: Dunk for Harold
When: Sunday June 25, 10am to 12pm
Where: Tikitapu (Blue Lake)