Canadian Geographic
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Pacific and Mountains

In the rain shadow

Where lush forests give way to parched landscapes
Parts of the Pacific Coast get 2,500 mm of rain and snow in a year; others, barely 500 mm.

Coast Range. The Coast Range is responsible for these variations. When warm, moisture-laden ocean air hits the range and is forced upward, the rising air cools, losing its ability to retain moisture. This results in heavy rainfall that feeds lush forests on the western slopes.

Interior B.C. On the eastern slopes, the descending air becomes warmer and retains moisture. This effect, called the “rain shadow,” creates the parched landscape of interior B.C.

The Rockies. Moving eastward, the air recovers moisture, which falls as snow on the Rockies. If the air is moisture-starved for long periods, the result may be forest fires in the dry mountain valleys and drought on the Prairies.

To learn more about our weather click here.


Lush forests This animation begins as a photograph of the feet of a B.C. forest in a beautiful mountain lake, with majestic mountains in the background. A menu offers further information on:
Coast range
Interior B.C.
The Rockies.

Clicking on any of them opens a diagram of the geography of each region.


On the next page:

Mountain zones

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Quiz :

Where does Canada export most of its wood products from British Columbia?