TORONTO -- Full-day kindergarten is now available across Ontario, though some of the classrooms are not yet ready, delayed by this winter's deep freeze, the province's education minister said Tuesday.

Liz Sandals marked the first day of school by visiting a Catholic elementary school, saying while not all the full-day kindergarten classrooms are currently available, the program is now fully rolled out. There are 265,000 kids enrolled this fall in the program for four- and five-year-olds at 3,600 schools.

"It may be a couple of weeks or it may be a month before the actual room is available, but those kids are in a room, they're getting the teaching and they're in class," Sandals said.

"We had a really, really, really cold winter last year and you can't start construction until the frost comes out of the ground, so all these construction projects to build new classrooms were about a month later starting."

Sandals said it's clear full-day kindergarten is helping students do better, even though there's no firm evidence yet to support that conclusion. Critics of full-day kindergarten should wait until the province gathers evidence on the first students to go through the program before declaring it is not a success, she said.

"Because we're just rolling the program out, the kids we're talking about are just starting to get to Grade 3," Sandals said.

Class size is an important issue, Sandals said, though she wouldn't say if she would put a cap on the number of children in a class. The beginning of the school year brings the "kindergarten dance," in which schools try to deal with an unexpected influx of kids whose parents registered them for kindergarten just last week instead of in February.

Sandals expressed optimism about contract negotiations with the province's teachers. She said she has met with each of the union presidents, who have told her they believe agreements can be reached, she said.

"The natural rhythm of school board negotiations ... is in fact that the collective agreement expires at the end of August, the negotiations start to ramp up in the fall and maybe it's next winter or next spring you eventually figure out an agreement," she said.

"So I have no expectation we're going to have an agreement next week, but I do have an expectation given the conversations and the good will I'm hearing from both school boards and unions that we will eventually come to an agreement."