Environment Canada has issued a severe thunderstorm watch for Hamilton, as approaching cold front has the possibility of bringing in a torrent of rain, high winds and hail.
The watch is affecting most of Southern Ontario and extends into Tuesday evening.
"Some of these thunderstorms have the potential to become severe with large hail, damaging winds and torrential rainfall," Environment Canada said in a statement. "Emergency Management Ontario recommends that you take cover immediately, if threatening weather approaches."
A severe thunderstorm could cause wind gusts up to 90 km/h, hail larger than 2 cm in diameter, or heavy rainfall.
The forecast for Tuesday night says the temperature in Hamilton could drop to as low as 13 C in the overnight, and is expecting winds of 30 km/h, gusting to 50 km/h.