Montreal's soggy July comes to an end

A flash of lightning turns night into day over Ile Perrot last Friday evening. It was just one of  the many thunderstorms generated this July from warm and moist air locked into the region. A record-breaking 212mm rain fell in Montreal for the month.

That was one wet July, record-breaking for many parts of the province. In Montreal, 212mm (8.4 inches) of rain was measured at Trudeau Airport. Many parts of the island had even more rainfall. There were multiple instances of flash flooding from heavy thunderstorms. That amount broke the record of 182.6mm (7.2 inches) set in 1980 at then Dorval Airport. The McGill University record from downtown Montreal set back in 1958 (246mm) was also eclipsed, with 265mm (10.4 inches) falling. The normal for a typical July in Montreal is 89mm (3.5 inches), so we were 237 percent of the normal value, so it was wet to say the least.

Rainfall amounts were 200-300 percent above normal values across southern Quebec this past month. Many regions established new monthly rainfall records. Meanwhile west-central Quebec and northern parts of the province remained usually hot and dry. This allowed many forest fires to continue burning. Over 1.5 million hectares have burned in Quebec this year to date. (ECCC Image)

At my home on Ile Perrot, I recorded 183.2mm (7.2 inches). Both Quebec City (265mm) and Sherbrooke (258mm) also established new monthly records. Sherbrooke measured 81.1mm in one day on July 10.

The heavy rain across portions of  Quebec City, the Saguenay and Eastern Townships south into Vermont and upstate New York produced widespread, historic flooding in many locations.

Along with the rain was plenty of humidity and severe weather. Besides the flash flooding and hail, three tornadoes occurred in July in the province. Two EF-0 tornadoes, capable of 130km/h winds occurred at Mirabel and Saint Thomas on July 13. Meanwhile on July 18, an EF-1 tornado occurred at Brompton in the Eastern Townships. The storm, capable of winds of up to 155km/h, resulted in damage to homes a barn, crops, several trees and hydro poles.

 As if that was not enough, July also featured multiple days of poor air quality from forest fire smoke and days on end of fog and elevated humidex readings in many parts of Quebec. Montreal reached a steamy humidex of 42C (107.6F) on both July 5 and 6. However, the cloud cover and frequent rain did result in lower daytime highs in general across southern Quebec, but the same conditions produced very mild overnight temperatures yielding above normal temperatures overall in many parts of the region. The average in Montreal was 22.8C (73F), above the normal of 21.2C (70.1F).

Northern parts of the province into Labrador were downright hot this past July. On July 4, the warmest temperature ever recorded at Kuujjuaq near Ungava Bay was observed at 34.3C (93.7F). This smashed the previous high of 25.6C (78.1F) set in 1962. 

August has started off cooler than normal, but dry for a moment or two. That will change tonight and Thursday, as a warm front will result in more heavy rain and thunderstorms across the Montreal region. The weekend at this time looks dry and warm, but rain returns once again to start next week.