Underwood has warmer summer afternoons than 91% of Canadian towns
On a normal January night the air cools to about −10.1°C. Only about 145 nights a year bring a frost, fewer than in 70% of Canadian towns. Precipitation peaks in June and eases off in February. Homes need heating from October to April, the months averaging under 10°C.
No ECCC station in Underwood has 1991–2020 normals; the page reads Toronto Buttonville (Airport), 6.0 km north-west, instead.
A year in Underwood at a glance
Each month’s typical high and low, in °C.
What stands out about Underwood’s climate
Compared with Canadian towns, with its place among towns of 2,500+ in Ontario beside it.
What a year in Underwood feels like
Seasons and months as ECCC’s 1991–2020 normals give them: a typical day’s high and low.
About 145 frosts and 126 warm days a year
Frost comes from October to May; in January almost every night freezes. 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
About 113 days a year bring 1 mm or more.
Rain and snow by month
Millimetres
Rain alone by month
Millimetres
146 cm of snow in a typical 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 Underwood
93% of a year’s heating need falls between October and April. Months averaging under 10°C: October to April.
Heating degree days total each day’s gap between its mean temperature and 18°C. Over a year, a home here needs less heating than 74% of Canadian towns.
Living with Underwood’s climate
What the normals mean for a garden, a day outside and the depth of winter.
The growing season between frosts lasts about 161 days, roughly 3 May to 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 →A wind chill below −20 is part of about 22 days a year here.
Count on some 55 humid days a year with the humidex past 30.
Extremes don’t show in averages: floods, wildfire smoke and ice storms are on Underwood’s hazards page.
Flood & hazards →ECCC’s normals location: Toronto Buttonville (Airport)
Toronto Buttonville (Airport) is a composite: ECCC joins 3 stations’ readings to make its 1991–2020 normals.
| Distance from the town | 6.0 km north-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), 20 km |
How Underwood compares
Compared with 2,611 towns and neighbourhoods of 2,500 or more across Canada; the dots mark the other normals locations in Ontario.
Nearby towns’ climate
The nearest places on a normals location of their own: those that share Underwood’s would only repeat its figures. Distances here run 15–22 km: that is how far the nearest places with figures are from Underwood.
Underwood 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 |
Two years in three, January’s average lands within 3.1°C of normal, against the steadier June
The thirty-year records stretch furthest in March: a low of −25.6°C in 2003 and a high of 26.3°C in 2012.
Where Underwood’s numbers come from
Averages over 30 years, not a forecast.
- Normals: the Canadian Climate Normals, 1991–2020, at Toronto Buttonville (Airport) (the closest location with all twelve months of 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 Underwood’s climate
How warm does Underwood get in summer?
Midsummer means July, with afternoons near 27.3°C on a typical day.
How cold does Underwood get in winter?
Overnight lows average −10.1°C in January, the coldest month.
How much rain and snow does Underwood get?
June is the wettest month at 87 mm and February the driest at 51 mm, for 862 mm over the year.
How long does snow stay on the ground?
About 76 days a year have 1 cm of snow or more on the ground.
Are these figures for Underwood itself?
They are borrowed from Toronto Buttonville (Airport), the nearest place to Underwood where ECCC publishes 1991–2020 normals.
Data Source: Environment and Climate Change Canada · ECCC Data Services End-use Licence Today’s forecast for Underwood →
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).