What September feels like in Montreal
For Montreal, September is early autumn on the calendar. Mild afternoons make it easy to spend hours outdoors. After dark the temperature drops clearly: nights are cool. The air is fairly humid, though at these temperatures it rarely feels oppressive.
Rain in Montreal in September
Showers are a regular feature, arriving about one day in 3. Rainy days are intense, averaging about 9.7 mm (0.4 in) — downpours rather than drizzle. Across the year Montreal averages about 8 mm per rainy day, so September is typical.
Daylight and sunshine in September
On 15 September the sun rises at about 6:31 am and sets around 7:08 pm local time, giving 12 h 37 min of daylight. Evenings are drawing in — 1 h 34 min less daylight than mid-August. Measured sunshine covers about 74% of the daylight — there are plenty of bright spells.
How September compares to the rest of the year
Ranked by average high, September comes out as the 4th warmest month in Montreal. Afternoons run 3.8°C (6.8°F) cooler than in August, with 21 mm less rain. The cooling trend carries on into October. The next month's average high: 13.7°C (56.7°F).
Who September suits
- Sightseeing: a good fit — the weather rarely gets in the way of a city walk.
- Parks & outdoor: a good fit — comfortable for long walks and picnics.
Tips for visiting Montreal in September
Versatile Layers
Days are noticeably warmer than nights — layers you can add or remove.
Rain Protection
Keep a small umbrella in your bag and wear shoes that cope with puddles.
Sunglasses
Frequent sunshine — sunglasses and a light hat.
Quick questions
How warm is Montreal in September?
It feels mild: typical highs are 21°C (69.8°F), with lows near 12.8°C (55°F).
Does it rain a lot in Montreal in September?
Quite a lot — 88 mm spread over about 9 days.
What should I wear in Montreal in September?
Pack versatile layers, rain protection and sunglasses. Add a layer for after dark.
Is September or October better for visiting Montreal?
September, clearly: it ranks #1 of 12 among Montreal's months, against #6 for the other. October is cooler and has more rainy days.