Hiking in a Rain Shadow

Kamloops sits in a physiographic region of BC called the Interior Plateau, which lies immediately to the east of the Coast Mountains. These mountains run roughly southeast-to-northwest and form a barrier to the dominant, moist air-flow from the Pacific Ocean, and result in a climate that is much drier and more continental than that of the coastal areas.

This happens because when the air is forced to rise over the mountains as it travels east, it cools and much of its moisture falls as precipitation on the windward slopes. The now drier air then warms again as it flows downhill on the leeward side, and the clouds dissipate. This region, where the precipitation is much less, is called a rain shadow.

Mara and Canyon
Left, Mt. Mara and Tranquille River Canyon in foreground

Rain-shadow climates are not just drier than those ‘on the other side of the mountain’, they are also warmer. In fact, the southern interior, and in particular those narrow fingers of land centered on the major river valleys there, experience hotter and drier summers than any other areas in the province. Kamloops has the hottest summers of any Canadian city, and only Whitehorse in the Yukon is drier.

These narrow river valleys make up a small climactic zone called the Bunchgrass Zone, which covers less than one percent of the total area of BC and is characterized by open grasslands where the climate is generally hostile to tree growth. But the very conditions that prevent the growth of forests are a blessing to hikers.

Kamloops lies in an area that is uniquely favorable for hiking. The Thompson River valley is flanked on both sides by lines of high hills, some with stunning perpendicular cliffs, from which sweeping vistas spread in all directions. The views to the north from the line of cliffs in the Buse lake Protected Area, and to the south from the summit of Mount Mara, are among the finest in the southern interior, and because of our climate these places can be reached year-round. The open terrain in the valley also provides excellent views without having to go high to get them, and the semi-arid climate has allowed geological features such as hoodoos to form which cannot exist anywhere else.

Hiking in a rain shadow means that where you are it is, on average, drier, sunnier and warmer than it is elsewhere, and you will probably have a beautiful view from almost anywhere.

grasslands and Al
Al in the Grasslands north of Kamloops

Al Budreau

Kamloops Backcountry Hikes