Expected heat wave could be longest of summer so far: Environment Canada

_ (Heat warning from Environment Canada ) _

9:55 PM EDT Monday 08 August 2016

Heat Warning in effect for:

 * 
Ottawa North - Kanata - Orléans

 * 
Ottawa South - Richmond - Metcalfe

Humidex values reaching near 40 are expected.

Yet another heat wave on the way.

A hot and humid airmass will return from the United States beginning Tuesday afternoon, when afternoon temperatures are forecast to reach the low 30s. Humidex values will slowly rise to the mid 30s in most areas on Tuesday.

The air mass will become considerably more humid Tuesday night, which will keep overnight temperatures near 20 in most areas. Hot and humid conditions under partly to mostly sunny skies are expected Wednesday through Friday. Afternoon temperatures will reach the low to mid 30s, and early morning minimum temperatures may briefly reach the low 20s. The warm and muggy nights will not provide much of a break from the almost relentless heat, even in the odd location where temperatures may briefly dip to the upper teens shortly before sunrise.

Some relief from the daytime heat is possible in a few locales near the shorelines of the Great Lakes if a breeze off the lake develops.

Humidex values peaking in the upper thirties to low 40s are expected beginning Wednesday as well.

This may be the longest and most significant heat wave of the summer so far.

Latest indications suggest a weak cold front, along with a chance of showers and thunderstorms, may move through sometime Friday night. If this occurs as forecast, some relief from the heat and humidity will be expected in time for next weekend.

Frequently visit neighbours, friends and older family members, especially those who are chronically ill, to make sure that they are cool and hydrated.

Reschedule or plan outdoor activities during cooler parts of the day.

Never leave people or pets in your care inside a parked vehicle or in direct sunlight.

Prepare meals that don’t need to be cooked in your oven.

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.

Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to storm.ontario@ec.gc.ca or tweet reports to #ONStorm.