Frost advisories also in effect for southern Saskatchewan and western Manitoba.
In these areas, temperatures are expected to drop to near or below the freezing mark and frost is possible overnight. As of 11 p.m., Calgary was not under a frost advisory but Edmonton and Medicine Hat were added at 9:34 p.m.
Rural locations are often colder at night and this is the reason the frost advisories are in effect for those areas.
If this advisory affects your community, be sure to protect sensitive plants and trees, and wash any frost off plants with a garden hose as soon as possible.
Frost advisories are issued when frost is expected earlier than normal. Calgary usually sees frost for the first time around Sep. 15 and Edmonton on Sep. 21.