Hot and humid airmass to make it feel like 40 in Ottawa today and Friday

It's a hot and humid start to August in Ottawa, with the humidex expected to make it feel like 40 today and Friday.

Environment Canada has issued a heat warning for Ottawa and eastern Ontario, warning a "heat event" will continue through Friday and possibly into the weekend.

"A hot and humid airmass is expected to arrive today," the weather agency said in a statement. "Maximum daytime temperatures of 30 to 32 degrees Celsius are expected, with humidex values near 40. Overnight minimum temperatures will be 19 to 21 degrees Celsius."

The temperature hit 30.5 C at 2 p.m., with the humidex making it feel like 39.

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The forecast calls for a high of 31 C on Thursday and 31 C on Friday, with the humidex making it feel like 39.

Ottawa will see a mix of sun and cloud today, with a 30 per cent chance of showers late this afternoon with the risk of a thunderstorm.

Partly cloudy tonight with a 30 per cent chance of showers early this evening. There is a risk of a thunderstorm. Low 20 C.

Friday will be mainly sunny.

The outlook for Saturday calls for mainly cloudy with a 30 per cent chance of showers. High 28 C.

Sunday will be cloudy with a 40 per cent chance of showers. High 25 C.

The normal temperatures for this time of year are a high of 26 C and a low of 16 C.

Tips to stay cool

Ottawa Public Health offers the following tips to stay cool:

• Drink plenty of water and avoid alcohol and caffeine.
• Avoid heavy outdoor activity.
• Wear a hat, light and loose-fitting clothing, sunscreen, and sunglasses when outside.
• Cool off in an air-conditioned space when available including malls, museums, libraries, and movie theatres.
• Cool off in the shade or at a park or green space.
• Use a fan and mist your skin with water.
• Take cool baths and showers as often as needed or soak hands or feet in cool water.
• Keep your home cool by closing blinds and curtains on any windows facing the sun.
• Open windows at night once the outdoor air is cooler than the indoor air; close windows in the morning before hotter air comes in.
• Use fans at night to help exhaust warm indoor air and/or bring in cool outdoor air.

The city's website has an interactive map listing places to cool off, including splash pads, parks and green spaces, community centres and Ottawa Public Library branches.

Wet July

July ended with Ottawa receiving 154 mm of rain.

Environment Canada says the normal precipitation for the month of July is 89 mm.

"Some areas in eastern Ontario, including Ottawa saw much higher amounts due to intense localized thunderstorms," Environment Canada said in its monthly review.

Here is a look at the July rainfall totals between 2015 and 2024

• 2024: 154 mm
• 2023: 142.4 mm
• 2022: 89 mm
• 2021: 104 mm
• 2020: 54 mm
• 2019: 52.1 mm
• 2018: 180 mm (61 mm on July 25 and 43 mm on July 23)
• 2017: 249 mm (79 mm on July 24, 42.6 mm on July 14 and 42 mm on July 1)
• 2016: 52.7 mm
• 2015: 40.8 mm