Photo: Pymouss · CC BY-SA 4.0Saint-Constant has warmer summer afternoons than 78% of Canadian towns
Nights in January average −13.5°C. Winter and summer sit 40°C apart. Precipitation is plentiful here, more than falls on 74% of Canadian towns. Warm coats and heating bills mark the months from October to April, when means dip under 10°C.
Saint-Constant has no ECCC normals station of its own: every figure here comes from Montréal Trudeau (Airport), 17 km north-west.
A year in Saint-Constant at a glance
Each month’s typical high and low, in °C.
What stands out about Saint-Constant’s climate
Compared with Canadian towns, with its place among towns of 2,500+ in Quebec beside it.
What a year in Saint-Constant feels like
Each season’s and each month’s usual high and low, 1991–2020.
About 146 frosts and 121 warm days a year
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
October is the wettest month and February the driest. About 122 days a year bring 1 mm or more.
Rain and snow by month
Millimetres
Rain alone by month
Millimetres
About 217 cm of snow a year
Expect snow from October to April, with about 52 cm in January, the snowiest month.
Snowfall by month
Centimetres
Snow on the ground by month
Centimetres at month’s end
Heating a home in Saint-Constant
93% of a year’s heating need falls between October and April. Months averaging under 10°C: October to April.
One degree below 18°C for one day makes one heating degree day; the year’s days are added together. A house here needs less heating than 62% of Canadian towns.
Living with Saint-Constant’s climate
What the normals mean for a garden, a day outside and the depth of winter.
Gardens get from about 29 April to 14 October without frost, around 167 days in all.
For long days outdoors, May, Jun, Jul, Aug and Sep bring highs of 17–27°C and lows of 8°C or more.
Parks & trails →Bitter wind chill, under −20, comes on about 40 days a year.
Roughly 50 days a year feel hotter than 30 once humidity is counted.
A normal year has no blizzard, flood or heat wave in it; Saint-Constant’s hazards page looks at those.
Flood & hazards →ECCC’s normals location: Montréal Trudeau (Airport)
Behind the 1991–2020 normals for Montréal Trudeau (Airport) are 3 stations, which ECCC combines into one record.
| Distance from the town | 17 km north-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, 21 km |
How Saint-Constant compares
Against the 2,611 Canadian towns and neighbourhoods of 2,500 or more, each read from its own normals location; the dots are the other locations those towns use in Quebec.
Nearby towns’ climate
Nearby places read from a different ECCC location (places on Saint-Constant’s own would show the same figures). No closer place has figures: this one lies 5 km from Saint-Constant.
| Town | July high | January low | Rain & snow |
|---|---|---|---|
| Saint-Constant Montréal Trudeau (Airport) | 26.7°C | −13.5°C | 1,041 mm |
| Candiac 5.4 km · L'Acadie | 26.6°C about the same | −13.6°C about the same | 1,041 mm |
Saint-Constant weather by month
Month by month, 1991–2020: the usual high, low and mean, the rain and snow, and the 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 |
January varies most from one year to the next (3.0°C), June least
Records from 1991 to 2020: no month spans more than March, between −26.9°C (1992) and 25.8°C (2012).
Where Saint-Constant’s numbers come from
Averages over 30 years, not a forecast.
- Normals: the 1991–2020 normals from ECCC for Montréal Trudeau (Airport), its nearest location with complete temperatures.
- Comparisons: every place of 2,500+ in Canada but the city hubs and the reserves, each on its nearest ECCC location.
- Not on this page: sunshine, absent from every 1991–2020 location, and an altitude correction, for want of the town’s own elevation.
Canadian Climate Normals 1991–2020 · ECCC Data Services End-use Licence. Data Source: Environment and Climate Change Canada
Questions about Saint-Constant’s climate
How warm does Saint-Constant get in summer?
July is the warmest month, with average highs of 26.7°C.
How cold does Saint-Constant get in winter?
Midwinter means January, when a typical night reaches −13.5°C.
How much rain and snow does Saint-Constant get?
Count on roughly 1,041 mm a year, heaviest in October (103 mm) and lightest in February (66 mm).
How long does snow stay on the ground?
About 101 days a year count as snow-covered, with 1 cm or more.
Are these figures for Saint-Constant itself?
No, the station behind them is Montréal Trudeau (Airport), beyond Saint-Constant’s boundary.
Data Source: Environment and Climate Change Canada · ECCC Data Services End-use Licence Today’s forecast for Saint-Constant →
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).