Photo: P199 · CC BY-SA 3.0Winter nights in Plympton-Wyoming are milder than in 83% of Canadian towns
July afternoons average 26.5°C. Summer afternoons here are warmer than in 65% of Canadian towns. From frozen January to warm July, readings climb 35°C. Plan time outside from June to September, when highs sit at 22–27°C.
ECCC publishes no normals for Plympton-Wyoming itself; the figures are those of Sarnia, 15 km west.
A year in Plympton-Wyoming at a glance
Each month’s typical high and low, in °C.
What stands out about Plympton-Wyoming’s climate
Compared with Canadian towns, with its place among towns of 2,500+ in Ontario beside it.
What a year in Plympton-Wyoming feels like
Each season’s and each month’s usual high and low, 1991–2020.
131 frost days and 124 days above 20°C a year
The frost season runs October to April, and January freezes nearly every night. Heat of 30°C or more comes on about 15 days a year.
Frost days by month
Average days at 0°C or below
Days above 20°C by month
Average days
About 871 mm of rain and snow a year
The most falls in June, the least in February. 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 112 cm of snow a year
From November to April snow is likely; January is the peak, at about 34 cm.
Snowfall by month
Centimetres
Snow on the ground by month
Centimetres at month’s end
Heating a home in Plympton-Wyoming
92% of a year’s heating need falls between October and April. Months averaging under 10°C: November to April.
Heating degree days total each day’s gap between its mean temperature and 18°C. A house here needs less heating than 86% of Canadian towns.
Living with Plympton-Wyoming’s climate
The averages read for the garden, the outdoors and the coldest and hottest days.
Warm afternoons without cold nights, 17–27°C and 8°C or more, mark Jun, Jul, Aug and Sep.
Parks & trails →Expect around 14 days a year when the wind chill sinks below −20.
Thirty-year normals hide the storms and the extremes: the hazards page has Plympton-Wyoming’s risks.
Flood & hazards →ECCC’s normals location: Sarnia
Sarnia is a composite: ECCC joins 4 stations’ readings to make its 1991–2020 normals.
| Distance from the town | 15 km west |
| Station altitude | 181 m |
| Completeness | meets the WMO “3 and 5” rule |
| WMO standard normals | No |
| Coldest reading, 1991–2020 | −28.0°C |
| Hottest reading, 1991–2020 | 37.9°C |
| Average wind | 15.0 km/h on average, most often from the south |
| Next-nearest location | Strathroy-Mullifarry, 39 km |
How Plympton-Wyoming 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 Plympton-Wyoming’s own would show the same figures). No closer place has figures: this one lies 20 km from Plympton-Wyoming.
| Town | July high | January low | Rain & snow |
|---|---|---|---|
| Plympton-Wyoming Sarnia | 26.5°C | −8.2°C | 871 mm |
| Watford 20 km · Strathroy-Mullifarry | 27.3°C 0.8°C warmer | −8.5°C about the same | 966 mm |
Plympton-Wyoming 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 | −0.9°C | −8.2°C | −4.6°C | 57 mm | 34 cm |
| February | 0.0°C | −7.9°C | −4.0°C | 48 mm | 20 cm |
| March | 5.0°C | −3.7°C | 0.6°C | 57 mm | 22 cm |
| April | 11.9°C | 1.5°C | 6.7°C | 79 mm | 4 cm |
| May | 18.7°C | 7.4°C | 13.1°C | 85 mm | 0 cm |
| June | 24.0°C | 13.0°C | 18.6°C | 93 mm | 0 cm |
| July | 26.5°C | 16.0°C | 21.3°C | 80 mm | 0 cm |
| August | 25.5°C | 15.3°C | 20.4°C | 71 mm | 0 cm |
| September | 22.2°C | 11.3°C | 16.7°C | 84 mm | 0 cm |
| October | 15.4°C | 6.0°C | 10.7°C | 78 mm | 1 cm |
| November | 8.0°C | 0.4°C | 4.2°C | 80 mm | 7 cm |
| December | 2.1°C | −4.4°C | −1.2°C | 60 mm | 25 cm |
| Year | 13.2°C | 3.9°C | 8.5°C | 871 mm | 112 cm |
A March here can run from −22.3°C to 27.9°C
February is the least predictable month: about two years in three its average lands within 2.9°C of the normal, −4.0°C. June is the steadiest, within 1.2°C.
Where Plympton-Wyoming’s numbers come from
Averages over 30 years, not a forecast.
- Normals: ECCC’s 1991–2020 Canadian Climate Normals for Sarnia, the nearest location with a full year of temperatures.
- Comparisons: a pool of Canadian towns and neighbourhoods of 2,500 or more, read alike; whole cities and reserves stay out of it.
- Not on this page: sunshine, not in ECCC’s 1991–2020 normals, and the effect of the town’s height, for which there is no figure.
Canadian Climate Normals 1991–2020 · ECCC Data Services End-use Licence. Data Source: Environment and Climate Change Canada
Questions about Plympton-Wyoming’s climate
How warm does Plympton-Wyoming get in summer?
On a normal day in July the thermometer climbs to 26.5°C, the warmest of the year.
How cold does Plympton-Wyoming get in winter?
At its coldest, in January, the normal low is −8.2°C.
How much rain and snow does Plympton-Wyoming get?
Rain and snow, with snow counted as water, total 871 mm a year; June leads with 93 mm and February trails with 48 mm.
Are these figures for Plympton-Wyoming itself?
They are the closest available: the normals for Sarnia, since Plympton-Wyoming has none.
Data Source: Environment and Climate Change Canada · ECCC Data Services End-use Licence Today’s forecast for Plympton-Wyoming →
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).