Photo: Veillg1 · CC BY-SA 4.0Grenville is wetter than 88% of Canadian towns: 1,178 mm of rain and snow a year
Midsummer highs settle at about 26.5°C. Precipitation peaks in October and eases off in February. By January nights alone, it runs colder than 67% of Canadian towns. Homes need heating from October to April, the months averaging under 10°C.
These are not Grenville’s own readings: ECCC keeps no normals there, so the page uses Lachute, 21 km east.
A year in Grenville at a glance
Each month’s typical high and low, in °C.
What stands out about Grenville’s climate
Compared with Canadian towns, with its place among towns of 2,500+ in Quebec beside it.
What a year in Grenville feels like
Seasons and months as ECCC’s 1991–2020 normals give them: a typical day’s high and low.
159 frost days and 115 days above 20°C a year
From October to May frost is routine, and in January it comes on almost every night. On about 19 nights a year the air falls below −20°C.
Frost days by month
Average days at 0°C or below
Days above 20°C by month
Average days
About 1,178 mm of rain and snow a year
Some 143 days a year see 1 mm of rain or snow or more.
Rain and snow by month
Millimetres
Rain alone by month
Millimetres
About 218 cm of snow a year
The snow season runs October to April; January brings the most, about 56 cm.
Snowfall by month
Centimetres
Snow on the ground by month
Centimetres at month’s end
Heating a home in Grenville
93% of a year’s heating need falls between October and April. Months averaging under 10°C: October to April.
ECCC sums, over the year, how many degrees each day’s average falls short of 18°C.
Living with Grenville’s climate
The averages read for the garden, the outdoors and the coldest and hottest days.
The growing season between frosts lasts about 143 days, roughly 12 May to 3 October.
For long days outdoors, Jun, Jul, Aug and Sep bring highs of 17–27°C and lows of 8°C or more.
Parks & trails →A typical year is calm by definition; Grenville’s hazards page covers the exceptions.
Flood & hazards →ECCC’s normals location: Lachute
Every temperature, frost, snow and degree-day figure on this page is the 1991–2020 normal ECCC publishes for Lachute.
| Distance from the town | 21 km east |
| Station altitude | 91 m |
| Completeness | at least 20 years |
| WMO standard normals | No |
| Coldest reading, 1991–2020 | −36.0°C |
| Hottest reading, 1991–2020 | 36.0°C |
| Next-nearest location | St-Jovite, 50 km |
How Grenville 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
The nearest places on a normals location of their own: those that share Grenville’s would only repeat its figures. Distances here run 31–40 km: that is how far the nearest places with figures are from Grenville.
| Town | July high | January low | Rain & snow |
|---|---|---|---|
| Grenville Lachute | 26.5°C | −14.7°C | 1,178 mm |
| Wendover 31 km · Angers | 26.2°C about the same | −16.5°C 1.8°C colder | 1,178 mm |
| Alexandria 37 km · Cornwall | 27.3°C 0.8°C warmer | −11.8°C 2.9°C milder | 1,006 mm |
Grenville weather by month
Average daily high and low, mean temperature, rain and snow (as water) and snowfall by month, 1991–2020.
| Month | High | Low | Mean | Rain & snow | Snow |
|---|---|---|---|---|---|
| January | −5.5°C | −14.7°C | −10.2°C | 97 mm | 56 cm |
| February | −3.6°C | −13.6°C | −8.3°C | 72 mm | 47 cm |
| March | 2.4°C | −7.2°C | −2.5°C | 74 mm | 34 cm |
| April | 11.0°C | 0.5°C | 5.9°C | 100 mm | 8 cm |
| May | 19.4°C | 7.4°C | 13.3°C | 89 mm | 0 cm |
| June | 24.1°C | 12.6°C | 18.4°C | 111 mm | 0 cm |
| July | 26.5°C | 15.1°C | 20.5°C | 112 mm | 0 cm |
| August | 25.4°C | 14.3°C | 19.8°C | 104 mm | 0 cm |
| September | 20.8°C | 9.9°C | 15.4°C | 114 mm | 0 cm |
| October | 12.8°C | 3.7°C | 8.4°C | 120 mm | 2 cm |
| November | 5.2°C | −2.3°C | 1.6°C | 93 mm | 17 cm |
| December | −1.9°C | −9.5°C | −6.0°C | 94 mm | 53 cm |
| Year | 11.4°C | 1.4°C | 6.4°C | 1,178 mm | 218 cm |
March has run from −30.5°C to 26.5°C in thirty years
The month to count on least is January: one year in three its average strays more than 3.2°C from −10.2°C. August moves least, typically by 1.0°C.
Where Grenville’s numbers come from
Averages over 30 years, not a forecast.
- Normals: ECCC’s 1991–2020 Canadian Climate Normals for Lachute, the nearest location with a full year of temperatures.
- Comparisons: Canadian towns and neighbourhoods of at least 2,500, each placed by its nearest location (city totals and reserves excluded).
- 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 Grenville’s climate
How warm does Grenville get in summer?
A normal July afternoon tops out at about 26.5°C, the year’s high point.
How cold does Grenville get in winter?
Of all twelve months, January has the coldest nights, about −14.7°C.
How much rain and snow does Grenville get?
Measured as water, a year brings 1,178 mm: 120 mm in October, the wettest month, and 72 mm in February, the driest.
How long does snow stay on the ground?
A layer of at least 1 cm stays down on about 128 days a year.
Are these figures for Grenville itself?
Not as such: Lachute is the nearest normals location, and Grenville has none.
Data Source: Environment and Climate Change Canada · ECCC Data Services End-use Licence Today’s forecast for Grenville →
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).