There are no entries from Hawke's Bay and East Coast.
There are confirmed games for the Tane (senior men), Wahine (women's) and Taiohi (Under 18) grades, while Davis said they remain hopeful of including Rangatahi (Under 20).
There will be roughly 3-4 teams for each grade, playing 30 minute matches.
"If it's [weather] like this on Saturday and Sunday, it's going to be hot," Davis said.
Vaan Rauhina, the tough 54-game veteran prop for Steelform Wanganui, will coach the Whanganui Tane, as his playing career remains on hold after last season's leg operation.
Games kickoff tomorrow at 10am and play through until 5pm, and then on Sunday from 11am-4pm.
Entry is free.