With 1306 points, Deloraine's victory has earned them a return trip to division two, according to NHSSA executive director Andrew McCarthy.

"They had some really outstanding athletes out there today ... they won quite easily in the end I think," he said.

The smaller sizes of competing schools made for a quieter day, with no records being broken in the lead up to division one on Friday.

"The number of people at St Leonards on Thursday won't be as great as the number on Friday with division one," McCarthy said.

"Riverside [High School] seems to dominate every year, we're just waiting for someone to knock them off but we don't know when that'll be.

"The standard wasn't great on Thursday but that varies from year-to-year."

Riverside has been the aggregate winner of the NHSSA division one carnival 18 years in a row.

In other news:

It would be the heat off the track, with Launceston's top of 26 degrees, that would impact Thursday's competition the most.

"There were a few withdrawals from some events with people worried they might get heatstroke ... but most of the events were well represented," McCarthy said.

"Kids really struggled in the 1500 and 800 metre events because of the heat but they did a really good job."

McCarthy anticipated the heat would once again be a factor in tomorrow's division one carnival.

"It should be a good day, might get even hotter than Wednesday. We've got to constantly remind kids about sunblock and keeping hydrated," he said.

The day did see a solid outing by the eight-athlete team from Flinders Island District High School, who finished fourth.

This was highlighted by Flinders runner Connor Wheatley, who finished first in the grades 9/10 200, 400, 800 and 1500-metre races.

"They don't come every year but they were really keen to get over," McCarthy said.

"I reckon they'll start coming over every year from now on .. they went really well."