On Thursday a team of judges will interview all the students, select the best projects in each of the age classes and award over 20 special prizes. Several thousand dollars' worth of prizes are being donated by science organisations.
Judge Jonathan Harrington said science and technology fairs provided a great chance for students to actively participate in science projects.
"Their enthusiasm is clear to see, and the fairs are a great way to get school students to make scientific research part of finding solutions to problems. They learn that science experiments must be researched, designed and analysed. These are very valuable life skills to learn."
The fair is open to the public on Thursday afternoon and Friday morning. Entry is free.
NIWA is a crown-owned research and consultancy company, with a global reputation as experts in water and atmospheric research. NIWA provides major sponsorship for many of the science fairs throughout New Zealand