Record rainfall for Montreal

Torrential rain slowed the evening commute in Montreal. A record-setting 67mm fell on the city in less than five hours Tuesday night. (ValleyWX Photo)

Tropical rains fell across southern Quebec and Ontario late on Tuesday, with a record 67mm at Trudeau Airport in Dorval, most of that falling between 2pm and 9pm. That amount shattered the previous 24-hour record for August 16 of 49.5mm, established in 1966. It also rapidly brought the August total for the city from nothing to 119mm in just four days. The average August rainfall for Montreal is 94.1mm. Heavy rain and strong winds created widespread power outages across the region. As of early Wednesday morning, nearly 100,000 Hydro Quebec customers were in the dark. That number has since fallen to around 35,000 as of noon, August 17. Hydro Quebec has not specifically mentioned the cause, but a substation in Mercier-Hochelaga-Maisonneuve was flooded and knocked offline last evening.

The rain and poor visibility may have also contributed to accidents in which two pedestrians were struck by cars, in different parts of the city. Some underpasses were also flooded, but for the most part the water drained well. The ground has been parched lately and water levels have been very low, so the runoff was quick.

Other amounts of rain reported last evening included 58mm at my home on L'Ile Perrot, 77.8mm downtown at the McTavish recording station, 75mm at Oka, 90mm in Wiarton, Ontario, 58mm in Kemptville, Ontario and 26mm in Ottawa. South of the border in Vermont, heavy localized rain from thunderstorms washed out a section of Route 100 in Duxbury.

Warm and humid weather will now be with us through the weekend, with highs from 28 to 30C (83 to 86F) and warm lows near 20C (68F). The humidex readings will climb from the low to middle 30s by the weekend. Scattered thunderstorm activity is possible over the weekend, in the soupy air mass.