Sunny days in mid-October in the GTA are usually something to celebrate.

But the warmer-than-usual temperatures mean we might not be getting as much of the brilliant fall foliage that Ontario residents can usually count on. Or we might have to wait longer than usual to get a look at the traditional fall hues.

“The warmer fall, so far, is definitely the main factor as to why the leaves are changing later this year,” said The Weather Network’s meteorologist Doug Gillham.

But Gillham cautioned the GTA is really at the beginning of the fall folliage season, so all may not be lost.

“Generally, we tend to peak in late October, but for cottage country, this is often the peak,” he said.

“I don’t think the season is going to be a dud, especially in the GTA, where there is still time to have those pigments build up in the leaves. It’ll just be a little bit later than usual,” added Gillham. “Cottage country is probably not going to be the most memorable season. It’s still pretty. We always get the yellows. It’s just how much of the reds and oranges do we get, as well?”

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Gillham says decreasing daylight, dropping temperatures and moisture trigger the colour changes.

Experts say three chemicals are responsible for pigments in a leaf, with chlorophyll producing green during the growing season, carotenoids providing a yellow hue after chlorophyll breaks down, and anthocyanins  leading to red, orange and golden colours.

“Certainly, north of here we’re not seeing as much colour,” said Gillham. “We’re running out of time to salvage that.  The question is, ‘Is it too little too late?’ Right now, we have some ideal conditions in that we are getting the colder nights this week and I don’t think it’s really too late for the GTA.”

Gillham noted there could be an issue as after this week’s colder night temperatures, the forecast is calling for the thermometer to hit the upper teens, and low 20s again.

“We’re going to go into a warmer-than-normal pattern by next weekend,” he said.

“And it looks like the rest of October and the first week of November will be warmer than normal, so we’re not going to have optimal condition. There are negatives in terms of the impact on the fall colours, but it’s really been a pleasant fall.”

— with files from CP.