Near-perfect late summer weather

The harvest moon will light up the evening sky on election day Monday, rising at 7:55pm in Montreal The Autumnal Equinox occurs Tuesday at 3:20pm. eastern time, heralding the end to summer 2021. The weather will be as perfect as it can possibly be for late September in southern Quebec and Ontario.

Fall officially arrives on Wednesday afternoon at 3:20pm eastern time, and with the exception a few high clouds, summer will end with near-perfect weather. There really is not much to add, strong high pressure is in control of the weather across eastern Ontario and southern Quebec and into Atlantic Canada. Expect clear, warm days, with increasing warmth and gusty winds as the week moves along.

A weak front settled across the region early Saturday morning, but as with just about every cold front this summer, it moved across Montreal with little fanfare, just a drop or two of moisture. Skies quickly cleared out leaving us with a beautiful day, and a high temperature of 24C (76F). 

As a matter of fact, 24C looks like the magic number this week. Expect sunshine through Wednesday and perhaps even into Thursday, with high temperatures either side of 24C. Overnight lows will start off fairly cool, in the upper single digits for some locations, as I write the current temperature is 11C (52F) here on Ile Perrot. By the middle of the week, overnight lows will be very mild under southerly winds, in the upper teens. The normal high/low for late September in Montreal, is 18C (65F) and 8C (48F).

Last Wednesday morning, a line of strong thunderstorms put down a quick 10 to 20mm of rain across the city. However conditions remain rather dry, with only 38.2mm of rain falling this month at Trudeau Airport. The normal for the entire month should be 89mm. The longer nights does mean there is dew present most mornings, which is helping a little.

The next chance for precipitation will arrive by Thursday as a frontal boundary and upper level low move across the Great Lakes and into Quebec. We can only hope this system brings some real rainfall.