Afternoon heat in Upper Thornhill Estates beats that of 91% of Canadian towns
Deep winter brings January lows near −10.1°C. By frosts alone, it ranks gentler than 70% of Canadian towns. Winter and summer sit 37°C apart. Warm coats and heating bills mark the months from October to April, when means dip under 10°C.
ECCC publishes no normals for Upper Thornhill Estates itself; the figures are those of Toronto Buttonville (Airport), 8.6 km east.
A year in Upper Thornhill Estates at a glance
Each month’s typical high and low, in °C.
What stands out about Upper Thornhill Estates’s climate
Compared with Canadian towns, with its place among towns of 2,500+ in Ontario beside it.
What a year in Upper Thornhill Estates feels like
Typical highs and lows by season and by month, from ECCC’s 1991–2020 normals.
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
About 862 mm of rain and snow a year
The most falls in June, the least in February. On about 113 days a year, 1 mm or more falls.
Rain and snow by month
Millimetres
Rain alone by month
Millimetres
146 cm of snow in a typical year
The snow season runs November to April; January brings the most, about 40 cm.
Snowfall by month
Centimetres
Snow on the ground by month
Centimetres at month’s end
Heating a home in Upper Thornhill Estates
93% of a year’s heating need falls between October and April. Months averaging under 10°C: October to April.
A day averaging 10 degrees under 18°C adds 10 to the total; warm days add nothing. In heating terms, homes need less heating than 74% of Canadian towns.
Living with Upper Thornhill Estates’s climate
What the normals mean for a garden, a day outside and the depth of winter.
About 161 days a year pass without frost, from an average last frost of 3 May to a first of 13 October.
For long days outdoors, Jun, Aug and Sep bring highs of 17–27°C and lows of 8°C or more.
Parks & trails →About 22 days a year bring a wind chill under −20, when bare skin chills fast.
The air feels heavier than 30 on the humidex for about 55 days a year.
Thirty-year normals hide the storms and the extremes: the hazards page has Upper Thornhill Estates’s risks.
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 | 8.6 km east |
| 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), 23 km |
How Upper Thornhill Estates compares
Against the 2,611 Canadian towns and neighbourhoods of 2,500 or more, each read from its own normals location; the dots are the other locations those towns use in Ontario.
Nearby towns’ climate
Places around Upper Thornhill Estates whose figures come from another normals location. The nearest places to Upper Thornhill Estates with figures are 19–29 km away.
| Town | July high | January low | Rain & snow |
|---|---|---|---|
| Upper Thornhill Estates Toronto Buttonville (Airport) | 27.3°C | −10.1°C | 862 mm |
| Toronto 19 km · Toronto (City) | 27.0°C about the same | −6.7°C 3.4°C milder | 823 mm |
| Bolton 26 km · Toronto Pearson (Airport) | 27.4°C about the same | −8.9°C 1.2°C milder | 807 mm |
| East Gwillimbury 27 km · Udora | 26.3°C 1.0°C cooler | −11.7°C 1.6°C colder | 883 mm |
| Bradford 27 km · Egbert | 26.0°C 1.3°C cooler | −11.3°C 1.2°C colder | 793 mm |
Upper Thornhill Estates 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 | −1.7°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 |
From year to year, January moves by 3.1°C, more than any month, and June least
Each bar spans a month’s coldest and warmest readings over thirty years; March’s run from −25.6°C in 2003 to 26.3°C in 2012.
Where Upper Thornhill Estates’s numbers come from
Averages over 30 years, not a forecast.
- Normals: Environment and Climate Change Canada’s 1991–2020 normals, Toronto Buttonville (Airport): the nearest of its locations with every month’s temperatures.
- Comparisons: all Canadian places of 2,500 or more except city totals and reserves, each read the same way.
- 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 Upper Thornhill Estates’s climate
How warm does Upper Thornhill Estates get in summer?
On a normal day in July the thermometer climbs to 27.3°C, the warmest of the year.
How cold does Upper Thornhill Estates get in winter?
In January, the coldest month, the typical low is −10.1°C.
How much rain and snow does Upper Thornhill Estates 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?
There is 1 cm of snow or more on the ground on roughly 76 days a year.
Are these figures for Upper Thornhill Estates itself?
No. ECCC measures normals at Toronto Buttonville (Airport), not in Upper Thornhill Estates; the page uses the nearest it has.
Data Source: Environment and Climate Change Canada · ECCC Data Services End-use Licence Today’s forecast for Upper Thornhill Estates →
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).