Vancouver’s fall season is a marvel in any year. But 2017 has been a special one.
Global BC viewers and CKNW listeners have written in with news of spectacular colours adorning the trees on Metro Vancouver streets and parks.
And they weren’t imagining anything if they thought that the colours were a touch or two prettier this year.
UBC forestry Prof. Robert Guy joined CKNW’s The Simi Sara Show on Thursday to talk about why the fall colours look especially vibrant this time around.
Good weather has been one contributor to the bright yellows and reds people have seen on the city’s trees.
“We had quite a lot of rain last week, and that, you know, is not the best for good colour,” Guy said. “But we did have nice, sunny weather and cool mornings, cold nights, and that’s ideal.”
The yellows may have been stimulated a little by the dry weather that Metro Vancouver experienced throughout the summer — though that’s usually responsible for brown leaves, he said.
But the reds have more to do with recent weather that started at the beginning of September, he said. They’ve been stimulated by sunny days, clear nights, cold mornings.
And recent rains helped to wipe away the drought, turning them red instead of brown, Guy added.
The colours have come as Vancouver has had slightly below average temperatures at night and above average sunshine hours throughout October, said Global BC meteorologist Kristi Gordon.
“That doesn’t mean our October has been dry and sunny, because it hasn’t,” she said. “We’ve had near average rainfall amounts and number of days with rain.
“But the key is when it wasn’t raining, there was little cloud and the sun was shining bright, more than in a typical fall.”
A chemical process goes into turning leaves to their stunning fall colours, Guy said.
Leaves are triggered to die by shorter days and longer nights. They die slowly if the weather’s warm, he explained.
Bright light breaks down chlorophyll, or the green pigment in the leaves, and that reveals their other pigments.
“As that’s happening in some trees, like a red maple, they will get redder,” Guy said.
“So not only are there pigments that were already exposed, but new pigments, red pigments may develop, and that’s stimulated by the bright light and the cold weather.”
WATCH: Taking in the fall colours – how to take great pictures.
The best time to see the leaves?
When the sun is low in the sky, and you’re walking in just the right direction.
“Things can look pretty spectacular, because the trees catch the light,” Guy said.
© 2017 Global News, a division of Corus Entertainment Inc.