London region to bake as Environment Canada issues heat warning

The sun is shown in this file photo. (Shutterstock/Maryloo)

Summer officially arrives a week from Tuesday, and southern Ontario is getting an early preview of the heat and humidity.

Temperatures are set to soar Wednesday and Thursday, with daytime highs climbing between 30C to 33C, and humidex values peaking near 40C.

As a result, Environment Canada has issued a two-day heat warning, and the Middlesex London Health Unit (MLHU) issued a two-day heat warning of its own as of Tuesday afternoon.

The impacted areas encompass much of southern Ontario, including London-Middlesex, Huron-Perth, Grey-Bruce, Elgin, Sarnia-Lambton, Windsor-Essex-Chatham-Kent, Oxford-Brant, Simcoe-Delhi-Norfolk, Hamilton, Dunnville-Caledonia-Haldimand, Niagara, and Waterloo-Wellington. 

The risks are greater for young children, pregnant women, older adults, people with chronic illnesses and people working or exercising outdoors.

The MLHU recommends the following tips to help cool down and avoid heat-related illness:

• Drink plenty of water throughout the day
• Never leave a child or pet in a parked car or sleeping outside in direct sunlight
• Avoid intense or moderately intense physical activity
• When possible, avoid spending too much time outdoors. If you must be outside, seek shade as much as possible, and plan outdoor activities in the early morning or evening
• Wear a wide-brimmed hat when outdoors
• Keep shades or drapes drawn and blinds closed on the sunny side of your home
• Take a cool bath or shower periodically or cool down with cool and wet towels
• Use fans to draw cool air at night, but do not rely on a fan as a primary cooling device during extended periods of excessive heat

A cold front will approach the region Thursday, sparking showers and thunderstorms. This cold front will clear the heat and humidity late Thursday.

A cooler and drier air mass will arrive Friday, with sunshine and comfortable temperatures expected for over the weekend.

The MLHU declares a heat warning when Environment Canada issues a forecast calling for a humidex of 40C or higher for two consecutive days, or Environment Canada issues a forecast calling for a daytime high of 31C or higher and a forecast low of 20C or higher for two consecutive days.

To learn more, you can visit the MLHU website.