We have a summer place near Cowley in SW Alberta.
Yesterday (21 Aug), the temp steadily dropped all afternoon and rain changed to heavy snow by 5 PM or so.
The elevation at our place is about 3500 feet.
The temp was officially 0°C at the Pincher Creek Airport, but was -1°C on my SUV.
The snow was heavy for a couple of hours. Some image URLs are below.
Thanks to Clive for these photos