Heat warning, severe thunderstorm watch in effect for Greater Montreal

There is both a heat warning and a severe thunderstorm watch in effect for Greater Montreal.

According to Environment Canada, a warm and humid air mass is expected to persist until Tuesday evening.

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“The combined values of temperature and humidity will produce a humidex factor of 37 to 40,” the weather agency noted.

“The risks are greater for young children, pregnant women, older adults, people with chronic illnesses and people working or exercising outdoors. Drink plenty of water even before you feel thirsty and stay in a cool place.”

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Environment Canada is asking people to check on older family, friends and neighbours to make sure they are staying cool and drinking water.

“Seek a cool place such as a tree-shaded area, swimming pool, shower or bath, or air-conditioned spot like a public building.”

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The weather agency added: “Outdoor workers should take regularly scheduled breaks in a cool place.”

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Once evening hits, Environment Canada says conditions are favourable for the development of severe thunderstorms that could produce strong wind gusts, large hail and heavy rain.

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“Intense lightning is likely with any thunderstorm that develops,” the agency said.

“Severe thunderstorms can produce tornadoes. Lightning kills and injures Canadians every year. Remember, when thunder roars, go indoors.”

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Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heatstroke or heat exhaustion.

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Severe thunderstorm watches are issued when atmospheric conditions are favourable for the development of thunderstorms that could produce large hail, damaging winds or torrential rainfall.