Meteorologists are warning people to be prepared for severe weather when it happens.
Geoff Coulson, a warning preparedness meteorologist with Environment Canada, said it looks like the province has been seeing more heavy-rain events in recent years.
"So in the coming decades, what we do expect to see is perhaps the longer periods of drought, but then punctuated by these very, very heavy rainfalls," Coulson says.
The meteorologist urges people to be careful when confronted with potential flash flooding. When a thunderstorm has dumped up to 100 mm in one place, he says, the rule of thumb is: Turn around, don't drown.
"Don't take that vehicle into the standing water," he warns. "Back up if it's safe to do so, find an alternate way around, don't drive through that water."
Tornado numbers are slightly up too. Ontario used to see an average 11 per year, but that's gone up slightly to 13, when you factor in the record 24 twisters in 2009.
Coulson reminds people the most important thing you can do is take cover when a tornado is upon you.
The best shelter, he says, is in solid building, preferably the basement or lowest level.
If you're in a multi-story building and don't have time to make it to ground, shelter on the floor you're on.
Coulson said the best place to be during a tornado is in the basement of a solid building.
"The rule of thumb is to put as many walls as you can between you and the outside," he says. "So if those wind forces or that tornado breaks through the glass of the exterior walls, you've got those additional walls between you and the storm."
Spreading the word about disasters will be a little different this season.
Emergency Management Ontario (EMO) will still issue red alerts for emergencies such as hazardous materials spills, but not for severe weather.
That will now be solely Environment Canada's responsibility. The agency will issue severe weather warnings and watches as normal, but red alerts will now only be issued in the aftermath of damaging weather.
"A community that's been particularly hard hit as Goderich was last year may want to issue a red alert to inform the province and the people of Ontario that the area is basically a disaster are," he says. "Significant damage, power lines are down, there's gas leaks. So basically stay away from this area unless you're on very essential business."