Winds will be from the southwest at 30-50 km/h this morning and the temperature will rise to 5 C.
Environment Canada is warning that following the passage of a cold front this afternoon, rain will change to snow and there will be a hard freeze as temperatures plummet.
However, a very strong cold front will cross the area Thursday afternoon changing the rain to snow with a threat for freezing rain.
People are asked to take extra care when walking or driving as roads and walkways may become slippery.
"What we're anxious about is a flash-freeze-type situation".
The mild weather in Waterloo region will be short-lived, as more cold weather and icy conditions are expected hit southern Ontario. "Snowfall amounts are expected to be limited to a few (centimetres)", Environment Canada's advisory read. As well as warning Torontonians to be cautious of falling temperatures, the alerts activate local services for vulnerable residents including additional shelter beds, overnight street outreach and other measures. If it is an emergency, call 911.