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Montréal weather by month: averages, rainfall & climate trends

A French-speaking island city where the Ottawa meets the Saint Lawrence, Montréal lives its seasons to the full: snow-deep, frosty winters and warm, festival-filled summers, with mercurial springs and autumns in between. Montréal weather by month: average temperatures, rainfall, records and how the climate has changed since 1940.

Today vs average

−0.8°Chigh near average

11° / 0°Today
12° / 4°Average
see today in detail →

How it's changed

+1.5°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–49151frost days a year now (2016–2025) · 163 in the 1940sfrost days a year · 163 in the 1940s7days above 30°C a year now (2016–2025) · 4 in the 1940sdays above 30°C · 4 in the 1940s+1.5°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 73 mmhigh −6°low −15°February, rain 69 mmhigh −5°low −14°March, rain 78 mmhigh 1°low −7°April, rain 98 mmhigh 10°low 0°May, rain 97 mmhigh 18°low 7°June, rain 105 mmhigh 23°low 13°July, rain 105 mmhigh 25°low 15°August, rain 104 mmhigh 24°low 14°September, rain 101 mmhigh 19°low 10°October, rain 101 mmhigh 12°low 4°November, rain 96 mmhigh 5°low −2°December, rain 92 mmhigh −3°low −11°wettest month July, 105 mm · 1,117 mm a yearsee month by month →

Right now

What it's doing today vs the historical average for this date.
Overcast

Right now

0.7°

−3°feels like
79%humidity
−3°dew point
10 km/hfrom S
UV index0.0
sunrise07:15sunset18:03day length10h 49m
TodayClear11°0°
MonClear13°5°
TueClear13°6°
WedClear10°3°
ThuClear13°4°
FriClear9°3°
SatClear10°1°

On this date: October 18

Today (forecast)
11° / 0°
Average for October 18
12° / 4°

High near average · −0.8°C

  • Record high: 22.8° · 1947
  • Record low: −5.5° · 1972
  • One year ago: 13° / 1°

Every October 18 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 18 on record (n = 87). Outlined dots are today's forecast.

Area we sample

Each city's history comes from one ERA5 grid cell, about 28 km across, shown by the dashed box. Near mountains or coasts, conditions can vary across the cell.

Location & data

Historical weather for Montréal is sampled from the ECMWF ERA5 reanalysis at 45.51°N, 73.59°W, with daily records since 1940.

Coordinates
45.51°N, 73.59°W
Time zone
America/Toronto
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

14 of the last 31 days were warmer than the historical average for that date. Average difference: −0.3°C.

Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above average; cool bars ran below. The dot inside the bar is the daily mean. The shaded band is the typical 10–90% range expected for that date. Average = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.

This date over the years

One dot per year, showing the mean temperature on this calendar date. Dots are warmer or cooler than the long-term average (dashed line); the shaded band is the typical 10–90% range, and the highlighted dot is today's forecast. Based on ERA5 reanalysis: modelled estimates, not station readings.

Weather by month

Average temperatures and rainfall for each month: a typical year, from the full record.

Climate overview

Montréal has a humid continental climate (Köppen Dfa/Dfb), set on an island where the Saint Lawrence and Ottawa rivers meet. Winters are long, cold and snowy, with windy and at times icy weather; summers are warm and humid. Spring and autumn are pleasant but notoriously fickle, prone to sudden, drastic swings in temperature.

Snow is a defining feature of the city for months at a time, and the cold can be sharp, so winter weather (heavy snowfalls and freezing rain) shapes daily life and infrastructure. The wide, four-season contrast between deep-freeze winters and hot, sticky summers is the hallmark of Montréal's climate.

July brings the year's peak warmth, with afternoons typically reaching 25.0°C and nights around 15.4°C. In January, the coolest month, afternoons reach about −6.4°C and nights dip to −15.0°C. Around 150 days a year dip below freezing.

The yearly total for Montréal comes to about 1,117 mm; monthly amounts range from 69 mm in February up to 105 mm in July.

Comparing the record's first decade with its most recent one, Montréal now averages 1.5°C warmer than it did in the 1940s. The last decade has also run wetter, about 10% above the long-term precipitation average.

Sources:en.wikipedia.orgbritannica.comweather.gc.ca

Climate graph (climograph)

July is the warmest month, January the coolest: a yearly swing of 31°C. Wettest month: July (~105 mm). Whole year averages ~1,117 mm of rain.

Bars = average monthly rainfall (right axis). Lines = average daily high and low (left axis). Average = each month's value averaged across every year of record (1940–2026).

Rainy days by month

About 114 rainy days a year: most in June (~10), fewest in February (~8).

Bars = average number of days with ≥ 2 mm per month. Hover for the monthly rainfall total.

Monthly wind

Average daily peak wind at 10 m, by month.

Monthly solar energy

Average daily incoming solar energy in megajoules per square metre: the record's own proxy for how sunny the month is.

Montréal month by month: what to expect

Typical conditions for each month, averaged across the full record (since 1940). Daylight is the time from sunrise to sunset. Record high/low are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainRainy daysDaylightRecord highRecord low
January−6.4°−15.0°73 mm98.9 h12.7° (1996)−37.5° (1957)
February−4.7°−13.6°69 mm810.1 h14.3° (1981)−35.5° (1967)
March1.4°−7.2°78 mm911.6 h24.7° (2012)−31.1° (1950)
April9.9°0.1°98 mm1013.3 h29.6° (1990)−15.6° (1954)
May17.9°7.0°97 mm1014.7 h34.9° (2020)−5.1° (1966)
June22.8°12.6°105 mm1015.5 h33.9° (2025)0.6° (1945)
July25.0°15.4°105 mm1015.2 h34.4° (1977)4.8° (1962)
August23.7°14.2°104 mm1013.9 h34.7° (2001)1.7° (1965)
September19.2°9.8°101 mm912.3 h31.6° (2002)−4.7° (1980)
October12.2°3.9°101 mm910.7 h28.6° (2025)−9.1° (1978)
November4.5°−2.2°96 mm109.2 h21.8° (2022)−21.1° (1949)
December−3.3°−10.9°92 mm108.5 h15.0° (2015)−33.5° (1989)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +1.5°C.

Each vertical stripe is one year. Color encodes how much that year's annual mean differed from the long-term average. Average = each year's annual mean compared to the average of all years (1940–2026). cooler ← → warmer

Annual mean temperature

Long-term trend: +0.20°C per decade.

One point per year, showing the temperature averaged across the whole year. The dashed line is the least-squares long-term trend. Based on ERA5 reanalysis: modelled estimates, not station readings.

Seasonal warming

Dec–Feb is warming fastest: +0.33°C per decade.

Each faint line is one three-month period's average per year; the bold dashed line is its long-term trend. Different parts of the year often warm at different rates. Based on ERA5 reanalysis: modelled estimates, not station readings.

Hot days vs frost days

Days ≥ 30°C per year: 3.5 early in the record → 7.0 recently. Frost days: 163 → 151.

Thin lines are raw yearly counts; thick lines are the smoothed trend that removes year-to-year noise. The hot-day threshold is auto-picked per city so the line actually moves. Average = a centered 5-year rolling average to smooth weather noise.

Yearly hot & cold extremes

All-time high in 2020, all-time low in 1957: 34.9°C / −37.5°C.

One point per year: the single hottest and coldest day recorded that year.

Annual rainfall

~1,117 mm/year on average. Last decade: +10% vs that average. Long-term trend: +18 mm per decade.

One bar per year of total rainfall. Dashed line is the long-term average. Average = the average annual rainfall across every year of record (1940–2026).

Day-by-day grid

Each tiny square is one calendar day across the full record, about 30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical average for that date (red = warmer, blue = cooler), Daily mean temp shows the absolute mean temperature for the day (useful to see seasons and heatwaves), and Precipitation shows daily rainfall (useful to spot wet/dry seasons and droughts). Average = the long-term average for that calendar date (1940–2026).

Frequently asked questions about Montréal

Which is the warmest month in Montréal?
On long-term average, the warmest month in Montréal is July (mean daily temperature of about 20.0°C) and the coolest is January (about −10.9°C).
How does today's temperature in Montréal compare to the historical average?
On October 18, 2026, Montréal is forecast to reach a high of 10.9°C and a low of 0.1°C. The long-term average for this date (the full record since 1940) is a high of 11.7°C and a low of 3.5°C, so today's high is 0.8°C cooler than that average.
How much has Montréal warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Montréal is about 1.5°C warmer.
How much does it rain in Montréal?
Montréal receives about 1,117 mm of precipitation per year on long-term average, with July typically the wettest month.
What is the average temperature in Montréal?
Over the full record (since 1940), the annual mean temperature in Montréal is about 5.5°C. The warmest month is July and the coolest is January.
What are the average temperatures in Montréal by month?
Average daily highs and lows for each month in Montréal (°C, full record since 1940): January −6°/−15°, February −5°/−14°, March 1°/−7°, April 10°/0°, May 18°/7°, June 23°/13°, July 25°/15°, August 24°/14°, September 19°/10°, October 12°/4°, November 5°/−2°, December −3°/−11°.
What is the weather like in Montréal in summer?
Summer in Montréal (June to August) is wet and pleasantly warm. Daytime highs sit at 23–25°C and nights at 13–15°C; July is the warmest month. Rain is steady at around 104 mm a month, spread over roughly 10 days.
What is the weather like in Montréal in winter?
December to February is winter in Montréal, and it is cold, with afternoons close to freezing. Afternoons run −6 to −3°C and nights −15 to −11°C; January is the coldest month. Snow is steady at around 78 mm of precipitation a month, spread over roughly 9 days.
What is the weather like in Montréal in spring?
March to May is spring in Montréal, and it is on the cool side. March is still 1°C in the afternoon and −7°C at night, May already 18°C and 7°C. Rain and snow fall on about 10 days a month, adding up to around 91 mm.
What is the weather like in Montréal in autumn?
In autumn, September through November, Montréal is cool. It cools from 19°C by day and 10°C at night in September to 5°C and −2°C in November. Rain falls on about 10 days a month, adding up to around 99 mm.
How many days a year does it rain in Montréal?
On long-term average, Montréal has about 114 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,117 mm.

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