A cold front arriving from northern Alberta was behind the sudden changes. The city hit a low of –11 C at around 1 a.m. Friday.

Eastern Canada, get ready for a temperature swing as we head through this week. After a warm start, a sharp cold front will send temperatures plummeting in the region, from west to east.

Another steamy day with the heat index value expected between 99-102 Tuesday.A heat advisory is in place through 8 a.m.