Canada Montreal Weather in September — Climate Guide
September in Montreal is Very Good
September is Very Good for Montreal.
September is Montreal's top shoulder season + foliage start. 11-20°C + 7.5 sunshine hours + hotels 30% cheaper than July-August. Mont-Tremblant (2-hour drive outskirts + gondola $22 + late September foliage peak) + POP Montreal (last week of September, indie music festival).
Korean Chuseok mid-late September drives Asian inbound spike + foliage combo peak. Sep 25-Oct 10 is the foliage photography peak window.
Travel score
Foliage starts + POP Montreal + Chuseok inbound peak
September Weather at a Glance
September averages 68°F / 20°C highs and 52°F / 11°C lows with 7.5 sunshine hours and 12 rainy days. Sunrise 6:35 AM, sunset 7:00 PM = 12h 25min daylight. The transformation from summer green to autumn red begins in the Laurentians late month — Mont Royal foliage starts to color first week of October.
September Travel Advice
Mont-Tremblant gondola foliage peak Sep 25-Oct 10 — book 2-3 weeks ahead. POP Montreal indie music tickets $22-74 (last week of September). Korean Chuseok travelers — book flights 2-3 months ahead. Lachine Canal BIXI cycling + autumn light is the canonical photo opportunity.
Flying In from Overseas
Korean Chuseok (mid-late September) drives Korean inbound spike. Japanese Silver Week + Respect-for-the-Aged Day adds Japanese tourists. Western European school year start. Direct flights from London $600-950, Paris $550-900, Frankfurt $600-950, NYC $180-400.
September Pricing Trends
Shoulder pricing returns: 4-star Downtown $180-410/night, 5-star $330-630, Plateau boutique $120-300. Chuseok week +20%. Mont-Tremblant gondola $22. POP Montreal $22-74.
Montreal September Weather Stats
Avg High
20°C
Avg Low
11°C
Rainy Days
12
87mm total
Sunshine
7.5h
Daily avg
Humidity
72%
Comfortable
UV Index
5
Moderate
Wind
11 km/h
Gusts 24
Sea Temp
17°C
Swimmable
Crowds
Busy
At attractions
September Sunrise & Sunset
Air Quality
PM2.5
10 μg/m³
PM10
20 μg/m³
Status
Good
Feels-Like Temperature & Wind
Feels like
Daytime
19°C
Nighttime
11°C
Humidity and wind affect how the actual temperature feels.
Wind
11 km/h
Max gust 24 km/h
Activities Recommended for September
September Travel Pros & Cons
Pros
- Foliage season starts (late September)
- Shoulder season — hotels 30% cheaper than Aug
- POP Montreal indie music + MUTEK digital art
Cons
- Korean Chuseok airfare spike + foliage demand
- Rain 12 days/month
- Cooling trend
September Events & Festivals
- POP Montreal — last week of September (indie music festival)
- Mont-Tremblant foliage season starts (late September peak)
- Korean Chuseok season (mid-late September)
- MUTEK Festival — late August to early September (digital + electronic art)
Montreal in September — Full Picture
September is Montreal's top shoulder season + foliage start. 11-20°C + 7.5 sunshine hours + hotels 30% cheaper than July-August. Mont-Tremblant (2-hour drive outskirts + gondola $22 + late September foliage peak) + POP Montreal (last week of September, indie music festival).
Korean Chuseok mid-late September drives Asian inbound spike + foliage combo peak. Sep 25-Oct 10 is the foliage photography peak window.
What to Wear & What to Pack
Early autumn. Long-sleeve + cardigan. Like mid-September in NYC. Foliage season starts mid-month. Mornings cool +10°C; afternoons +20°C. Pack a layer + waterproof shell.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
10.7°C
1°C
13/mo
Summer (Jun·Jul·Aug)
25°C
14.7°C
11.7/mo
Autumn (Sep·Oct·Nov)
Current13°C
5°C
12.7/mo
Winter (Dec·Jan·Feb)
-3.3°C
-12°C
13.3/mo
Montreal Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| -5° | -14° | 14d·78mm | 3h | 75% | 1 | Quiet | Low season | |
| -3° | -12° | 12d·62mm | 4.5h | 72% | 2 | Quiet | Low season | |
| 2° | -6° | 13d·75mm | 5.5h | 70% | 3 | Quiet | Shoulder | |
| 11° | 1° | 13d·80mm | 7h | 65% | 5 | Moderate | Shoulder | |
| May (Best) | 19° | 8° | 13d·75mm | 8h | 62% | 6 | Moderate | Shoulder |
| June (Best) | 24° | 13° | 12d·87mm | 9.5h | 65% | 8 | Busy | Peak |
| July (Best) | 26° | 16° | 12d·90mm | 10h | 67% | 9 | Very busy | Peak |
| August (Best) | 25° | 15° | 11d·88mm | 9h | 70% | 7 | Very busy | Peak |
| September (Best) | 20° | 11° | 12d·87mm | 7.5h | 72% | 5 | Busy | Peak |
| 13° | 5° | 12d·78mm | 6h | 75% | 3 | Moderate | Shoulder | |
| 6° | -1° | 14d·92mm | 3.5h | 78% | 2 | Quiet | Low season | |
| -2° | -10° | 14d·88mm | 2.5h | 78% | 1 | Busy | Peak |
View Other Months
Montreal September Hotel Picks
Frequently Asked Questions
Is September a good time to visit Montreal?
Montreal in September is Very Good. Tourist crowds are busy and flight/hotel prices are peak.
What's the average temperature in Montreal in September?
Montreal September averages a high of 20°C and a low of 11°C.
Does it rain much in Montreal in September?
Montreal September averages 87mm of rainfall over about 12 rainy days.
What should I wear in Montreal in September?
Early autumn. Long-sleeve + cardigan. Like mid-September in NYC. Foliage season starts mid-month. Mornings cool +10°C; afternoons +20°C. Pack a layer + waterproof shell.
What time are sunrise and sunset in Montreal in September?
Montreal September sunrise is 06:35 and sunset is 19:00, with 12h 25m of daylight.
What's the air quality like in Montreal in September?
Montreal September air quality (AQI) averages 32, rated Good. PM2.5 averages 10μg/m³.
What activities are recommended in Montreal in September?
In September, Montreal is great for Mont-Tremblant foliage start (late Sep), POP Montreal indie music, Mont Royal foliage.
Is September peak season in Montreal?
Montreal September crowds are busy and prices are peak. Advance reservations are strongly recommended.
Best Months to Visit Montreal
View Other Months
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.