Photo: P199 · CC BY-SA 3.0Afternoon heat in Long Sault beats that of 91% of Canadian towns
The depth of winter brings overnight lows near −11.8°C. Only about 140 nights a year bring a frost, fewer than in 72% of Canadian towns. Seasons differ by 39°C, from the coldest nights to the warmest afternoons. If you like long walks, May, June, August and September offer highs of 20–26°C.
Long Sault has no ECCC normals station of its own: every figure here comes from Cornwall, 15 km east.
A year in Long Sault at a glance
Each month’s typical high and low, in °C.
What stands out about Long Sault’s climate
Compared with Canadian towns, with its place among towns of 2,500+ in Ontario beside it.
What a year in Long Sault feels like
Seasons and months as ECCC’s 1991–2020 normals give them: a typical day’s high and low.
140 frost days and 125 days above 20°C a year
The frost season runs October to April, and January freezes nearly every night. Deep cold, under −20°C, comes on about 8 nights a year.
Frost days by month
Average days at 0°C or below
Days above 20°C by month
Average days
Rain and melted snow: about 1,006 mm a year
October is the wettest month and February the driest. On about 134 days a year, 1 mm or more falls.
Rain and snow by month
Millimetres
Rain alone by month
Millimetres
198 cm of snow in a typical year
Snow falls from November to April, most of all in January (about 51 cm).
Snowfall by month
Centimetres
Snow on the ground by month
Centimetres at month’s end
Heating a home in Long Sault
94% of a year’s heating need falls between October and April. Months averaging under 10°C: October to April.
A heating degree day is one degree of shortfall below 18°C for one day, summed over the year. Homes here need less heating than 71% of Canadian towns.
Living with Long Sault’s climate
What the normals mean for a garden, a day outside and the depth of winter.
The comfortable months for a day outside, highs of 17–27°C and nights of 8°C or more: May, Jun, Aug and Sep.
Parks & trails →The normals describe a typical year, not its worst days; the hazards page covers Long Sault’s.
Flood & hazards →ECCC’s normals location: Cornwall
Cornwall is one of the 450 places where ECCC publishes 1991–2020 normals.
| Distance from the town | 15 km east |
| Station altitude | 64 m |
| Completeness | meets the WMO “3 and 5” rule |
| WMO standard normals | No |
| Coldest reading, 1991–2020 | −32.0°C |
| Hottest reading, 1991–2020 | 37.5°C |
| Next-nearest location | St-Anicet, 46 km |
How Long Sault 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
Nearby places read from a different ECCC location (places on Long Sault’s own would show the same figures). No closer places have figures: these lie 31–44 km from Long Sault.
| Town | July high | January low | Rain & snow |
|---|---|---|---|
| Long Sault Cornwall | 27.3°C | −11.8°C | 1,006 mm |
| Morrisburg 31 km · Kemptville | 26.8°C 0.5°C cooler | −14.0°C 2.2°C colder | 925 mm |
| Limoges 35 km · Angers | 26.2°C 1.1°C cooler | −16.5°C 4.7°C colder | 930 mm |
| Embrun 37 km · Ottawa (Airport) | 27.0°C about the same | −14.3°C 2.5°C colder | 930 mm |
| Saint-Anicet 44 km · St-Anicet | 26.7°C 0.6°C cooler | −13.0°C 1.2°C colder | 1,047 mm |
Long Sault 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 | −3.8°C | −11.8°C | −7.8°C | 80 mm | 51 cm |
| February | −2.1°C | −10.6°C | −6.4°C | 63 mm | 48 cm |
| March | 3.5°C | −5.3°C | −0.9°C | 64 mm | 35 cm |
| April | 11.8°C | 2.0°C | 6.9°C | 83 mm | 11 cm |
| May | 19.8°C | 8.8°C | 14.3°C | 85 mm | 0 cm |
| June | 24.6°C | 14.1°C | 19.3°C | 95 mm | 0 cm |
| July | 27.3°C | 17.0°C | 22.2°C | 97 mm | 0 cm |
| August | 26.3°C | 16.2°C | 21.2°C | 83 mm | 0 cm |
| September | 22.0°C | 11.8°C | 16.9°C | 99 mm | 0 cm |
| October | 14.1°C | 5.7°C | 9.7°C | 100 mm | 1 cm |
| November | 6.9°C | −0.3°C | 3.3°C | 82 mm | 16 cm |
| December | 0.0°C | −6.7°C | −3.3°C | 75 mm | 37 cm |
| Year | 12.5°C | 3.4°C | 8.0°C | 1,006 mm | 198 cm |
A January here can run warm or cold, its average moving by about 3.0°C; the steadiest month is June
Over 1991–2020, March saw both −27.0°C (2003) and 26.0°C (1998), the widest span of any month.
Where Long Sault’s numbers come from
Averages over 30 years, not a forecast.
- Normals: the 1991–2020 normals from ECCC for Cornwall, its nearest location with complete temperatures.
- Comparisons: all Canadian places of 2,500 or more except city totals and reserves, each read the same way.
- 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 Long Sault’s climate
How warm does Long Sault get in summer?
In July, the warmest month, the typical high is 27.3°C.
How cold does Long Sault get in winter?
A typical January night falls to −11.8°C, the year’s low point.
How much rain and snow does Long Sault get?
Count on roughly 1,006 mm a year, heaviest in October (100 mm) and lightest in February (63 mm).
Are these figures for Long Sault itself?
Not as such: Cornwall is the nearest normals location, and Long Sault has none.
Data Source: Environment and Climate Change Canada · ECCC Data Services End-use Licence Today’s forecast for Long Sault →
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).