Summer arrives in force in Longueuil, hotter than in 78% of Canadian towns
Deep winter brings January lows near −13.5°C. The seasons are far apart: from a winter night to a summer afternoon the average spans 40°C. Precipitation is plentiful here, more than falls on 74% of Canadian towns. The furnace earns its keep from October to April, the months that average under 10°C.
Longueuil has no ECCC normals station of its own: every figure here comes from Montréal Trudeau (Airport), 23 km west.
A year in Longueuil at a glance
Each month’s typical high and low, in °C.
What stands out about Longueuil’s climate
Compared with Canadian towns, with its place among towns of 2,500+ in Quebec beside it.
What a year in Longueuil feels like
Each season’s and each month’s usual high and low, 1991–2020.
Frost on 146 days, 20°C on 121
The frost season runs October to April, and January freezes nearly every night. Some 12 nights a year drop under −20°C.
Frost days by month
Average days at 0°C or below
Days above 20°C by month
Average days
Rain and melted snow: about 1,041 mm a year
The most falls in October, the least in February. Some 122 days a year see 1 mm of rain or snow or more.
Rain and snow by month
Millimetres
Rain alone by month
Millimetres
217 cm of snow in a typical year
Snow falls from October to April, most of all in January (about 52 cm).
Snowfall by month
Centimetres
Snow on the ground by month
Centimetres at month’s end
Heating a home in Longueuil
93% of a year’s heating need falls between October and April. Months averaging under 10°C: October to April.
Degree days add up how far each day’s mean temperature falls below 18°C over a year. In heating terms, homes need less heating than 62% of Canadian towns.
Living with Longueuil’s climate
Gardening, time outside, winter cold and summer heat, from the 1991–2020 normals.
Tender plants are usually safe from around 29 April until frost returns near 14 October: about 167 days.
Warm afternoons without cold nights, 17–27°C and 8°C or more, mark May, Jun, Jul, Aug and Sep.
Parks & trails →About 40 days a year bring a wind chill under −20, when bare skin chills fast.
The humidex tops 30 on about 50 days a year: muggy days to plan around.
Bad-weather days, from blizzards to floods, get their own page for Longueuil: the hazards page.
Flood & hazards →ECCC’s normals location: Montréal Trudeau (Airport)
ECCC builds the Montréal Trudeau (Airport) normals from 3 stations’ records over 1991–2020, joined where one replaced another.
| Distance from the town | 23 km west |
| Station altitude | 36 m |
| Completeness | meets the WMO “3 and 5” rule |
| WMO standard normals | No |
| Coldest reading, 1991–2020 | −31.8°C |
| Hottest reading, 1991–2020 | 36.6°C |
| Average wind | 15.4 km/h on average, most often from the west |
| Next-nearest location | L'Acadie, 26 km |
How Longueuil compares
Placed among 2,611 Canadian towns and neighbourhoods of 2,500+, each on its nearest normals location; each dot is another location used in Quebec.
Nearby towns’ climate
Places around Longueuil whose figures come from another normals location. Distances here run 6–12 km: that is how far the nearest places with figures are from Longueuil.
| Town | July high | January low | Rain & snow |
|---|---|---|---|
| Longueuil Montréal Trudeau (Airport) | 26.7°C | −13.5°C | 1,041 mm |
| Brossard 6.4 km · L'Acadie | 26.6°C about the same | −13.6°C about the same | 1,041 mm |
| Boucherville 9.4 km · L'Assomption | 26.6°C about the same | −16.0°C 2.5°C colder | 1,041 mm |
Longueuil weather by month
Each month’s normals, 1991–2020: high, low, mean, precipitation and snowfall.
| Month | High | Low | Mean | Rain & snow | Snow |
|---|---|---|---|---|---|
| January | −5.0°C | −13.5°C | −9.2°C | 86 mm | 52 cm |
| February | −3.4°C | −12.4°C | −8.0°C | 66 mm | 47 cm |
| March | 2.4°C | −6.5°C | −2.0°C | 77 mm | 37 cm |
| April | 11.3°C | 1.1°C | 6.2°C | 90 mm | 15 cm |
| May | 19.4°C | 8.3°C | 13.9°C | 86 mm | 0 cm |
| June | 24.2°C | 13.8°C | 19.0°C | 84 mm | 0 cm |
| July | 26.7°C | 16.7°C | 21.7°C | 91 mm | 0 cm |
| August | 25.7°C | 15.6°C | 20.6°C | 94 mm | 0 cm |
| September | 21.1°C | 10.9°C | 16.0°C | 89 mm | 0 cm |
| October | 13.2°C | 4.5°C | 8.9°C | 103 mm | 1 cm |
| November | 6.1°C | −1.7°C | 2.3°C | 84 mm | 16 cm |
| December | −1.2°C | −8.7°C | −5.0°C | 92 mm | 48 cm |
| Year | 11.7°C | 2.3°C | 7.0°C | 1,041 mm | 217 cm |
In March, anything from −26.9°C to 25.8°C
Bars run from each month’s record low to its record high over 1991–2020; January is the month whose average wanders most from year to year (±3.0°C around −9.2°C), June the one that wanders least (±1.1°C).
Where Longueuil’s numbers come from
Averages over 30 years, not a forecast.
- Normals: the Canadian Climate Normals, 1991–2020, at Montréal Trudeau (Airport) (the closest location with all twelve months of temperatures).
- Comparisons: every Canadian town and neighbourhood of 2,500 or more, each read from its own nearest location; city totals and reserves are left out.
- Not on this page: sunshine, not in ECCC’s 1991–2020 normals, and the effect of the town’s height, for which there is no figure.
Canadian Climate Normals 1991–2020 · ECCC Data Services End-use Licence. Data Source: Environment and Climate Change Canada
Questions about Longueuil’s climate
How warm does Longueuil get in summer?
The warmest month is July, when afternoons average 26.7°C.
How cold does Longueuil get in winter?
At its coldest, in January, the normal low is −13.5°C.
How much rain and snow does Longueuil get?
Rain and snow, with snow counted as water, total 1,041 mm a year; October leads with 103 mm and February trails with 66 mm.
How long does snow stay on the ground?
Count on about 101 days of snow cover a year, 1 cm or deeper.
Are these figures for Longueuil itself?
Not exactly. Longueuil lacks a normals station, so Montréal Trudeau (Airport) supplies the figures.
Data Source: Environment and Climate Change Canada · ECCC Data Services End-use Licence Today’s forecast for Longueuil →
Adapted from Statistics Canada (Census of Population 2021, population estimates 2025, 2021 census boundaries) under the Statistics Canada Open Licence; this does not constitute an endorsement by Statistics Canada. Neighbourhood names in some cities © OpenStreetMap contributors (ODbL).