Photo: Pymouss · CC BY-SA 4.0Summer afternoons in Châteauguay are warmer than in 78% of Canadian towns
The depth of winter brings overnight lows near −13.5°C. Temperatures cover 40°C across the year, low to high. By precipitation alone, it ranks wetter than 74% of Canadian towns. An umbrella or a shovel earns its place on about 122 days a year with 1 mm or more.
These are not Châteauguay’s own readings: ECCC keeps no normals there, so the page uses Montréal Trudeau (Airport), 12 km north.
A year in Châteauguay at a glance
Each month’s typical high and low, in °C.
What stands out about Châteauguay’s climate
Compared with Canadian towns, with its place among towns of 2,500+ in Quebec beside it.
What a year in Châteauguay feels like
Typical highs and lows by season and by month, from ECCC’s 1991–2020 normals.
Frost on 146 days, 20°C on 121
From October to April frost is routine, and in January it comes on almost 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.
Rain and snow by month
Millimetres
Rain alone by month
Millimetres
Snowfall: about 217 cm in a normal 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 Châteauguay
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. That means homes here need less heating than 62% of Canadian towns.
Living with Châteauguay’s climate
What the normals mean for a garden, a day outside and the depth of winter.
Tender plants are usually safe from around 29 April until frost returns near 14 October: about 167 days.
Afternoons of 17–27°C and nights of at least 8°C arrive in May, Jun, Jul, Aug and Sep.
Parks & trails →On some 40 days a year the wind chill drops past −20; mitts and a scarf earn their place.
Plan shade and water for about 50 days a year above 30 on the humidex.
For blizzards, floods and wildfire, turn to Châteauguay’s hazards page.
Flood & hazards →ECCC’s normals location: Montréal Trudeau (Airport)
Montréal Trudeau (Airport) is a composite: ECCC joins 3 stations’ readings to make its 1991–2020 normals.
| Distance from the town | 12 km north |
| 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, 31 km |
How Châteauguay compares
Compared with 2,611 towns and neighbourhoods of 2,500 or more across Canada; the dots mark the other normals locations in Quebec.
Nearby towns’ climate
Nearby places read from a different ECCC location (places on Châteauguay’s own would show the same figures). The nearest place to Châteauguay with figures is 14 km away.
| Town | July high | January low | Rain & snow |
|---|---|---|---|
| Châteauguay Montréal Trudeau (Airport) | 26.7°C | −13.5°C | 1,041 mm |
| Saint-Rémi 14 km · L'Acadie | 26.6°C about the same | −13.6°C about the same | 1,041 mm |
Châteauguay 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 |
A January here can run warm or cold, its average moving by about 3.0°C; the steadiest month is June
Bars run from each month’s record low to its record high since 1991. March spans the most, from −26.9°C (1992) to 25.8°C (2012).
Where Châteauguay’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: Canada’s towns and neighbourhoods of 2,500+ (no city totals, no reserves), each through its own nearest location.
- Not on this page: sunshine, which none of ECCC’s 450 locations publishes for 1991–2020, and the town’s own height above sea level, so no figure is adjusted for altitude.
Canadian Climate Normals 1991–2020 · ECCC Data Services End-use Licence. Data Source: Environment and Climate Change Canada
Questions about Châteauguay’s climate
How warm does Châteauguay get in summer?
July is the warmest month, with average highs of 26.7°C.
How cold does Châteauguay get in winter?
Overnight lows average −13.5°C in January, the coldest month.
How much rain and snow does Châteauguay get?
Some 1,041 mm falls in a year. Most of it comes in October (103 mm), the least 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 Châteauguay itself?
Not directly: Châteauguay has no ECCC normals of its own, and Montréal Trudeau (Airport) stands in for it.
Data Source: Environment and Climate Change Canada · ECCC Data Services End-use Licence Today’s forecast for Châteauguay →
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).