The heatwave continues for Sarnia-Lambton.
A heat warning remained in effect Monday and Environment Canada upgraded a severe thunderstorm watch to a warning just after 4 p.m.
Areas of thunderstorms developed over lower Michigan and were tracking eastward with the main threats being torrential downpours of 50 millimetres per hour and isolated wind gusts of 90 kilometres per hour.
Meteorologist Peter Kimbell said it will become cooler and less humid Tuesday with a comfortable low of 15 C (59 F) Tuesday night.
"Weather is kind of cyclical; it's a series of waves going up and down like a roller coaster, and we're in the warm phase right now," said Kimbell. "We've seen those muggy temperatures on Saturday, Sunday and Monday, we'll see a bit of an improvement Tuesday and further improvement still on Wednesday, with a high around 25 C. We'll probably return to warmer temperatures on the weekend."
There's always the chance of heavy thunderstorms in hot, humid conditions but Kimbell said there's not a great chance of severe weather Monday.
There was a tornado warning for Chatham-Kent late Sunday afternoon but there have been no reports of funnel clouds touching down.
Environment Canada's Dave Rodgers said there was some damage reported by a trained weather spotter.
"He saw quite a few trees and hydro poles down in the Kent Bridge area," Rodgers. "And I guess there were around 500 people without power in that area, and there was also reports of marble-sized hail."
Some Hydro One customers west of Thamesville and near Kent Bridge were still without power Monday morning.
Environment Canada said heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.
The risks are greater for young children, pregnant women, older adults, individuals with chronic illnesses and those working or exercising outdoors.
The national weather agency says the hot and humid air can also bring deteriorating air quality.
We may get some brief respite from heat Monday as showers or thunderstorms are possible.
We're reminded to drink plenty of water and stay in a cool place and to never leave people or pets inside a parked vehicle.
