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The chinook

Calgary’s reprieve from the grasp of winter

Last Updated: Mar. 6, 2013

Along the eastern slopes of the Rocky Mountains, the chinook wind provides a welcome respite from the long winter chill.

Few people spend very much time along the eastern slopes without experiencing these warm winds.

The change can be dramatic. On Jan. 11, 1983, the temperature in Calgary rose 30 C — from –17 C to 13 C — in four hours, and on Feb. 7, 1964, the temperature rose 28 C, and the humidity dropped by 43 per cent.

Animation: How do chinooks happen?

Current temp.
A chinook usually begins with a sudden change in wind direction over  the Pacific ocean, towards the west or southwest, and a rapid  increase in wind speed.
Strong wind
Warm & moist
Warm & dry
Cooling & losing moisture
Forced to climb over the rockies, the weather phenomenon cools down  at a rate of half a degree for every 100 metres it rises.  Once it crests the summit of the mountains, it begins to move downhill, warming at a rate of one degree for every 100 metres.
As it comes down the mountains the temperature in Calgary can rise dramatically. 
If Calgary was -5 C before the chinook, the temperature would riseby 20 C, making Calgary feel like +15 C.
Strong warm, dry wind

Why does it make an arch?

The high crest of the wind creates a distinctive cloud band parallel to the mountains called a chinook arch.

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The effects of chinooks


  • Relief from sub–zero temperatures.
  • Highly strung people may begin to shake or fidget.
  • Susceptible people may get headaches or suffer nervous disorders.
  • Psychologically, many people feel "better."

Vegetation and soil

  • Soil moisture is lost, and the high winds may result in soil loss.
  • Many trees, like white birch, cannot survive the rapid temperature fluctuations.
  • Trees may begin to photosynthesize, losing moisture and dehydrating.
  • Leaves may sprout only to be killed by the next frost.
  • It may cause violent grass or forest fires, or cause small fires to spread quickly.


  • Removal of snow provides winter grazing for livestock.
  • If the temperature drops rapidly following a chinook, a crust of ice may form on the snow which makes grazing difficult and may result in injuries to animal's legs.
  • Wire fences can become electrified due to the strong positive electrical charge in the air. Cattle have been electrocuted in this way.

Does this weather phenomenon happen in other parts of the world?

It does happen elsewhere, regionally these winds are known by many different names.

Source: Environment Canada, NOAA, Meteocentrale