Afternoon heat in Cornell beats that of 91% of Canadian towns
Deep winter brings January lows near −10.1°C. June is the wettest month, February the driest. Frost is rarer than in 70% of Canadian towns: about 145 nights a year drop below freezing. Expect about 145 frosty starts a year, days when the air falls to freezing.
Borrowed figures: Cornell has no normals station, so these come from Toronto Buttonville (Airport), 12 km west.
A year in Cornell at a glance
Each month’s typical high and low, in °C.
What stands out about Cornell’s climate
Compared with Canadian towns, with its place among towns of 2,500+ in Ontario beside it.
What a year in Cornell feels like
Each season’s and each month’s usual high and low, 1991–2020.
Frost on 145 days, 20°C on 126
From October to May frost is routine, and in January it comes on almost every night. Some 6 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 862 mm a year
Some 113 days a year see 1 mm of rain or snow or more.
Rain and snow by month
Millimetres
Rain alone by month
Millimetres
About 146 cm of snow a year
Snow falls from November to April, most of all in January (about 40 cm).
Snowfall by month
Centimetres
Snow on the ground by month
Centimetres at month’s end
Heating a home in Cornell
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. In heating terms, homes need less heating than 74% of Canadian towns.
Living with Cornell’s climate
The averages read for the garden, the outdoors and the coldest and hottest days.
Plant out after about 3 May; the first frost of autumn usually arrives near 13 October, leaving roughly 161 days without frost.
Mild days and mild nights together (17–27°C by day, 8°C or more at night) belong to Jun, Aug and Sep.
Parks & trails →Expect around 22 days a year when the wind chill sinks below −20.
On some 55 days a year the humidex climbs past 30.
What averages leave out, the floods and ice storms, is on Cornell’s hazards page.
Flood & hazards →ECCC’s normals location: Toronto Buttonville (Airport)
Behind the 1991–2020 normals for Toronto Buttonville (Airport) are 3 stations, which ECCC combines into one record.
| Distance from the town | 12 km west |
| Station altitude | 198 m |
| Completeness | meets the WMO “3 and 5” rule |
| WMO standard normals | No |
| Coldest reading, 1991–2020 | −35.2°C |
| Hottest reading, 1991–2020 | 37.8°C |
| Average wind | 12.2 km/h on average, most often from the north |
| Next-nearest location | Toronto (City), 28 km |
How Cornell 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 Cornell whose figures come from another normals location. Cornell has few close neighbours with figures, so the list reaches 11–25 km out.
| Town | July high | January low | Rain & snow |
|---|---|---|---|
| Cornell Toronto Buttonville (Airport) | 27.3°C | −10.1°C | 862 mm |
| Pickering 11 km · Oshawa | 25.7°C 1.6°C cooler | −8.9°C 1.2°C milder | 906 mm |
| Toronto 23 km · Toronto (City) | 27.0°C about the same | −6.7°C 3.4°C milder | 823 mm |
| Uxbridge 25 km · Udora | 26.3°C 1.0°C cooler | −11.7°C 1.6°C colder | 883 mm |
Cornell weather by month
Each month’s normals, 1991–2020: high, low, mean, precipitation and snowfall.
| Month | High | Low | Mean | Rain & snow | Snow |
|---|---|---|---|---|---|
| January | −1.7°C | −10.1°C | −6.0°C | 64 mm | 40 cm |
| February | −1.0°C | −10.1°C | −5.6°C | 51 mm | 34 cm |
| March | 4.6°C | −5.0°C | −0.2°C | 52 mm | 20 cm |
| April | 11.8°C | 1.2°C | 6.5°C | 79 mm | 7 cm |
| May | 19.3°C | 7.4°C | 13.4°C | 80 mm | under 1 cm |
| June | 24.6°C | 13.0°C | 18.8°C | 87 mm | 0 cm |
| July | 27.3°C | 15.6°C | 21.5°C | 85 mm | 0 cm |
| August | 26.3°C | 14.8°C | 20.6°C | 72 mm | 0 cm |
| September | 21.9°C | 10.4°C | 16.2°C | 83 mm | 0 cm |
| October | 14.3°C | 4.3°C | 9.4°C | 71 mm | 1 cm |
| November | 7.4°C | −0.8°C | 3.3°C | 77 mm | 12 cm |
| December | 1.5°C | −5.8°C | −2.2°C | 63 mm | 33 cm |
| Year | 13.0°C | 2.9°C | 8.0°C | 862 mm | 146 cm |
January varies most from one year to the next (3.1°C), June least
Records from 1991 to 2020: no month spans more than March, between −25.6°C (2003) and 26.3°C (2012).
Where Cornell’s numbers come from
Averages over 30 years, not a forecast.
- Normals: the 1991–2020 normals from ECCC for Toronto Buttonville (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: a sunshine figure (ECCC published none for 1991–2020) and any lapse-rate correction for height, as the town has no elevation here.
Canadian Climate Normals 1991–2020 · ECCC Data Services End-use Licence. Data Source: Environment and Climate Change Canada
Questions about Cornell’s climate
How warm does Cornell get in summer?
On a normal day in July the thermometer climbs to 27.3°C, the warmest of the year.
How cold does Cornell get in winter?
Deep winter means January, when nights average −10.1°C.
How much rain and snow does Cornell get?
862 mm a year counting snow as water. The wettest month is June (87 mm); the driest, February (51 mm).
How long does snow stay on the ground?
A layer of at least 1 cm stays down on about 76 days a year.
Are these figures for Cornell itself?
They describe Toronto Buttonville (Airport), the nearest normals location, rather than Cornell itself.
Data Source: Environment and Climate Change Canada · ECCC Data Services End-use Licence Today’s forecast for Cornell →
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).