Alberta is in a semi-arid, continental climate regime. This means we are generally removed from the moderating effects the ocean and as a result are relatively cool and dry at our northern latitude. Alberta experiences a full range of seasons and large temperature variability over the year.

For most of the province (except in the higher foothills and in the mountains), average annual precipitation is less than the average annual evaporation. Relatively high evaporation shapes how lake levels in the province respond to short-term (year-to-year) variability and longer-term fluctuations in climate, like drought. In general, net evaporation becomes less significant as you move north. The southeast part of the province has the highest evaporation losses meaning that large-scale irrigation projects are needed to provide enough water for productive crops.

Average precipitation varies not only throughout the year but also across the province. The mountains receive the most moisture, with much of the rest of Alberta lying under a "rain-shadow" effect. The Rocky Mountains provide a topographic barrier to the large-scale inflow of moist Pacific air. Moisture-laden air masses off the coast of British Columbia are cooled as they are forced to rise upslope against the mountains. This generates heavy precipitation over the mountains. However, the opposite effect occurs on the Alberta side of the Rockies, where air masses already depleted of much of their moisture, move down slope onto the plains. As the dry air moves down slope, it expands and warms, which results in little precipitation.