Fall arrives in Ottawa with warm temperatures and rain

While fall has officially kicked off, the warm weather is going to stick around a little bit longer.

Environment Canada’s future projections forecast above seasonal temperatures throughout September and much of October.

Fall officially began at 2:19 p.m. with highs in Ottawa reaching 23 C, with a humidex making it feel like 28.

Those temperatures will remain steady for the week, with overnight lows in the teens.

The 30-year average temperature for Ottawa in September is 15.3 C.

A particularly dry summer will also give way to a rainy start to autumn.

Thunderstorms can be expected throughout the day Monday and overnight into Tuesday. While Wednesday may provide some reprieve, showers are forecasted to return Thursday and Friday.

Colourful leaves

Just because it may not feel like fall, doesn’t mean it won’t look like fall.

In fact, Ian Laidlaw, district manager at Ottawa’s Davey Tree Expert Co. office, said he expects the leaves to begin changing colour earlier this year, but the oranges, reds and yellows won’t be as bright.

That’s because temperature is not the only factor in determining when and how leaves change colour. They are impacted by a variety of climatic conditions.

The first indication of leaves changing is when the days start getting shorter.

“As the days get shorter, then the leaves stop getting as much sunlight and they start changing colours,” Laidlaw told CityNews.

But while the temperatures remain warm, the lack of rain throughout the summer impact how the leaves look.

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“When we’re in drought conditions like we’ve had for months, the tree will utilize it’s water in places other than in leaf and chlorophyll growth and production,” Laidlaw said.

He said the trees are quite literally using the water they can get to stay alive, rather than producing the beautiful colours we are used to seeing in the fall.

The extreme heat that characterized the summer has also contributed to stress in trees which have made them weaker and more susceptible to disease.

Basically, Laidlaw said, “they have no idea what time of year it is anymore”.

If the leaves begin to change earlier, that also means they’ll fall earlier, leaving branches bare as the warm weather appears to be fending off winter for as long as possible.

Tree health

Laidlaw said if you have trees on your property that are showing signs of stress, it is best to call an arborist.

He said arborists can help to strengthen trees through fertilization, pruning and other health assisting measures which help them get through stressful times.