Weather in Winnipeg in September

Prime time. If you get to pick your dates, September is the one. Highs average 19.8 °C, lows 8.3 °C, and rain falls on 11 days — nothing in the month is working against you.

September ranks 2 of 12 in Winnipeg. Only August scores clearly higher, and the difference is small enough to be settled by price rather than weather.

Rain on 11 days, 2 of them heavy. Enough to need a plan B, not enough to need a plan around it. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

Averages flatten a month, and this one hides a few things: it never really gets hot: not one day in an average September reaches 30 °C. Across the twenty years measured, the hottest September day reached 31.7 °C and the coldest night fell to -5.1 °C, and the wettest single day dropped 33 mm — roughly 55% of the month's rain in one day.

September is moderately variable: 18 mm in the driest year against 133 mm in the wettest, around an average of 60 mm. Roughly two Septembers in three land near that average, and the third does something else entirely.

Wind is light at 11.4 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 71%.

How September sits in the year

The month is on the way down: 5.7 °C cooler than August, with October dropping another 9.7 °C. The first week and the last are not the same trip.

Daylight in September

12.7 hours of daylight, losing 1.8 hours across the month. That is between Winnipeg's extremes of 16.3 and 8.1 hours, so days are long enough not to constrain the plan.

An inland climate

Winnipeg has no sea to moderate it, and it shows: 48.9 °C separates the hottest afternoon of the year from the coldest night. That is a genuinely continental range, and it means summer and winter here are barely the same place.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

September in Winnipeg versus nearby

If Winnipeg is one option among several, the nearby comparison is worth making. Regina is close enough to be a coin toss — within a degree on temperature, 4 days less rain. Thunder Bay is close enough to be a coin toss — within a degree on temperature, 2 days more rain.

So: September is effectively as good as it gets here — 0 points behind August, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in Winnipeg

See all twelve months in Winnipeg, or where else to go in September.