Organisations taking part include Whanganui District Council's civil defence emergency management team, Whanganui District Health Board's bowel screening service, Red Cross, Community Legal Advice Whanganui (CLAW), Birthright, Neighbourhood Support and many others.
"There's a theme of safety, but that's quite broad," Tamehana said.
"It might be the Whanganui Public Health Unit taking people through an activity of 'shooting' the measles virus, or it be might Horizons helping people with driver licensing."
The Family Fun Day has been held every year since 2016, except for last year when it was cancelled due to the Covid-19 lockdown.
"The Whanganui community needs some fun. A lot of people have had it hard over the past 12 months," Tamehana said.
"It's important that everything is free so everyone can take part."