Calgarians saw an unusual number in the weather forecast for their city this week: 37.

That's the forecast high, in degrees Celsius, for this Friday.

If the temperature indeed reaches that mark, it would be the highest ever recorded in Calgary, based on records going back to 1881.

There's one catch to the forecast, however.

The forecast high of 37 C assumes the smoke currently blanketing Calgary from B.C. wildfires clears out by Friday. (Environment Canada)

If all the smoke that's currently blanketing the city sticks around, it could push temperatures lower.

"Our model at this point in time … is based on there not being smoke," Brian Proctor, a meteorologist with Environment and Climate Change Canada, said Wednesday morning.

The latest air quality models suggest the smoke may indeed stick around longer than previously thought, Proctor said, so the forecast is likely to change later in the week.

"Our forecasters are making adjustments right through the period but they're not really adjusting where we get out into the Friday-Saturday timeframe yet," he said.

"They're pretty much completely tied up with trying to make things right for today, tonight, tomorrow and tomorrow night."

The smoke effect

Heavy smoke has been wafting eastward from forest fires in British Columbia, and that tends to keep things cooler than they would otherwise be during the daytime.

"The smoke particles reflect the incoming solar radiation — the sun's energy — and bounce it back up into the upper atmosphere and out to space," Proctor said.

It was about four degrees cooler than forecast in Edmonton on Tuesday, he added, due to heavy smoke blanketing Alberta's capital.

The forecast will be updated as Friday approaches and while there's a good chance the smoke will prevent Calgary from setting an all-time temperature record, Proctor said that's still possible, depending on which way the winds blow between now and then.

"If the smoke isn't as intense as we think it could be, we could definitely see that 37," he said.

Highest temperatures ever recorded in Calgary:

36.1 C — July 25, 1933

36.1 C — July 15, 1919

35.6 C — July 22, 1936

35.6 C — Aug. 3, 1914

35.3 C — July 26, 1984

— Source: Environment and Climate Change Canada

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