Frosty mornings in Westmount are scarcer than in 75% of Canadian towns
Midsummer highs settle at about 26.6°C. September is the wettest month, February the driest. Summer afternoons here are warmer than in 70% of Canadian towns. Plan for rain or snow on about 128 days a year, the days with 1 mm or more.
Figures: ECCC’s 1991–2020 normals for London (15 km north-east).
A year in Westmount at a glance
Each month’s typical high and low, in °C.
What stands out about Westmount’s climate
Compared with Canadian towns, with its place among towns of 2,500+ in Ontario beside it.
What a year in Westmount feels like
Typical highs and lows by season and by month, from ECCC’s 1991–2020 normals.
139 frost days and 128 days above 20°C a year
From October to May frost is routine, and in January it comes on almost every night. About 11 days a year top 30°C.
Frost days by month
Average days at 0°C or below
Days above 20°C by month
Average days
About 962 mm of rain and snow a year
Rain and snow by month
Millimetres
Snowfall: about 152 cm in a normal year
Expect snow from October to April, with about 43 cm in January, the snowiest month.
Snowfall by month
Centimetres
Snow on the ground by month
Centimetres at month’s end
Snowfall: Strathroy-Mullifarry, 29 km away (London records no complete year of it).
Heating a home in Westmount
92% 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. Homes here need less heating than 79% of Canadian towns.
Living with Westmount’s climate
Gardening, time outside, winter cold and summer heat, from the 1991–2020 normals.
Plant out after about 3 May; the first frost of autumn usually arrives near 16 October, leaving roughly 165 days without frost.
Highs of 17–27°C with nights of 8°C or more come in Jun, Jul, Aug and Sep.
Parks & trails →On some 18 days a year the wind chill drops past −20; mitts and a scarf earn their place.
Muggy heat with a humidex over 30 arrives on about 55 days a year.
A normal year has no blizzard, flood or heat wave in it; Westmount’s hazards page looks at those.
Flood & hazards →ECCC’s normals location: London
Behind the 1991–2020 normals for London are 3 stations, which ECCC combines into one record.
| Distance from the town | 15 km north-east |
| Station altitude | 278 m |
| Completeness | meets the WMO “3 and 5” rule |
| WMO standard normals | No |
| Snowfall from | Strathroy-Mullifarry, 29 km |
| Coldest reading, 1991–2020 | −29.1°C |
| Hottest reading, 1991–2020 | 37.0°C |
| Average wind | 14.0 km/h on average, most often from the west |
| Next-nearest location | Strathroy-Mullifarry, 29 km |
How Westmount 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 Ontario.
Nearby towns’ climate
Places around Westmount whose figures come from another normals location. Westmount has no close neighbour with figures; the nearest is 16 km away.
| Town | July high | January low | Rain & snow |
|---|---|---|---|
| Westmount London | 26.6°C | −9.1°C | 962 mm |
| Oneida 41 16 km · Strathroy-Mullifarry | 27.3°C 0.7°C warmer | −8.5°C 0.6°C milder | 966 mm |
Westmount 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 | −1.6°C | −9.1°C | −5.4°C | 79 mm | 43 cm |
| February | −0.6°C | −9.0°C | −4.8°C | 63 mm | 32 cm |
| March | 4.6°C | −4.5°C | 0.1°C | 67 mm | 20 cm |
| April | 12.2°C | 1.4°C | 6.8°C | 89 mm | 5 cm |
| May | 19.3°C | 7.7°C | 13.5°C | 89 mm | under 1 cm |
| June | 24.4°C | 13.2°C | 18.8°C | 86 mm | 0 cm |
| July | 26.6°C | 15.3°C | 21.0°C | 81 mm | 0 cm |
| August | 25.7°C | 14.4°C | 20.1°C | 67 mm | 0 cm |
| September | 22.1°C | 10.5°C | 16.3°C | 93 mm | 0 cm |
| October | 14.7°C | 5.0°C | 9.9°C | 83 mm | 2 cm |
| November | 7.5°C | −0.3°C | 3.6°C | 88 mm | 13 cm |
| December | 1.4°C | −5.2°C | −2.0°C | 79 mm | 37 cm |
| Year | 13.0°C | 3.3°C | 8.2°C | 962 mm | 152 cm |
The month with the widest range: March, −25.6°C to 27.2°C
February is the least predictable month: about two years in three its average lands within 3.0°C of the normal, −4.8°C. June is the steadiest, within 1.1°C.
Where Westmount’s numbers come from
Averages over 30 years, not a forecast.
- Normals: ECCC’s 1991–2020 Canadian Climate Normals for London, the nearest location with a full year of temperatures.
- Other locations: a location missing months of precipitation or snow is filled from the nearest that has them all, never mixed month by month.
- Comparisons: the 2,500-plus towns and neighbourhoods of Canada, each read from its closest normals location; whole cities and reserves aren’t counted.
- Not on this page: hours of sunshine, missing from the 1991–2020 normals, and a height correction: the town has no elevation on file.
Canadian Climate Normals 1991–2020 · ECCC Data Services End-use Licence. Data Source: Environment and Climate Change Canada
Questions about Westmount’s climate
How warm does Westmount get in summer?
Peak warmth comes in July, at about 26.6°C by mid-afternoon.
How cold does Westmount get in winter?
Lows sink to −9.1°C on an average January night.
How much rain and snow does Westmount get?
Over twelve months, rain and melted snow come to 962 mm; the range runs from 63 mm in February to 93 mm in September.
Are these figures for Westmount itself?
Almost: ECCC’s London location, which gives these figures, lies a short way outside Westmount.
Data Source: Environment and Climate Change Canada · ECCC Data Services End-use Licence Today’s forecast for Westmount →
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).