Tauranga Girls' College principal Pauline Cowens said there were very strong winds that came over the school and lasted about five minutes.
Mrs Cowens said the school's sale shades were damaged and branches had fallen.
Table umbrellas and outdoor furniture were scattered throughout the staff outdoor area.
"I don't know if you would call it a tornado but it was enough to bend poles in the court yard." said Mrs Cowen.
"I was surprised with how quick it was. It came through the front of the school and then it was gone." said Mrs Cowens.
Shrink wrap around the hall was also blown onto the school grounds.
Mrs Cowens said students were told to to stay indoors over a 20 minutes period before heading outside.
"I didn't want to alarm anybody but it was just interesting." said Mrs Cowens.