The official beginning of autumn is still a few weeks away, but residents in southern Alberta are expected to experience an abrupt change in temperatures over the next 24 hours.

The temperature and weather shift is forecasted to be so abrupt that Environment Canada issued a special weather statement for many regions in the province Saturday.

The City of Calgary is under that advisory, which states that while Saturday's high temperatures are expected to hit 30 C, it will be a much different story by the evening hours.

The agency says a system of cold air will drop the daytime high temperatures into the 10 to 15 C range throughout the rest of the weekend and bring plenty of rain. By the time it wraps up Monday evening, the agency says between five to 15 mm will have fallen.

Albertans and others in the mountain parks are also expected to see the return of an old friend.

"Currently, snowfall is expected to remain in and near the mountain parks, however there is a chance of seeing mixed precipitation in areas along lower elevations of the foothills, including Calgary," the statement reads.

Environment Canada also states there is a risk of frost expected in most of Alberta both Monday and Tuesday mornings. It's expected to be highest in the central and southern regions.