Photo: The Town of Ajax · CC BY 3.0Frost comes to Ajax less often than to 84% of Canadian towns
High summer brings afternoon highs near 25.7°C. The year swings widely: the coldest month’s nights and the warmest month’s afternoons are 35°C apart. Warm coats and heating bills mark the months from October to April, when means dip under 10°C.
Borrowed figures: Ajax has no normals station, so these come from Oshawa, 14 km north-east.
A year in Ajax at a glance
Each month’s typical high and low, in °C.
What stands out about Ajax’s climate
Compared with Canadian towns, with its place among towns of 2,500+ in Ontario beside it.
What a year in Ajax feels like
Seasons and months as ECCC’s 1991–2020 normals give them: a typical day’s high and low.
130 frost days and 107 days above 20°C a year
Frost comes from October to April; in January almost every night freezes. About 4 days a year top 30°C.
Frost days by month
Average days at 0°C or below
Days above 20°C by month
Average days
906 mm of precipitation in a typical year
June brings the most rain and snow; February, the least. On about 115 days a year, 1 mm or more falls.
Rain and snow by month
Millimetres
Rain alone by month
Millimetres
Snowfall: about 102 cm in a normal year
The snow season runs November to April; January brings the most, about 34 cm.
Snowfall by month
Centimetres
Snow on the ground by month
Centimetres at month’s end
Heating a home in Ajax
92% of a year’s heating need falls between October and April. Months averaging under 10°C: October to April.
The count adds up, day by day, how far the mean temperature falls short of 18°C. In heating terms, homes need less heating than 81% of Canadian towns.
Living with Ajax’s climate
The averages read for the garden, the outdoors and the coldest and hottest days.
A normal year gives the garden about 167 frost-free days, roughly 30 April to 15 October.
Warm afternoons without cold nights, 17–27°C and 8°C or more, mark Jun, Jul, Aug and Sep.
Parks & trails →The normals describe a typical year, not its worst days; the hazards page covers Ajax’s.
Flood & hazards →ECCC’s normals location: Oshawa
Behind the 1991–2020 normals for Oshawa are 2 stations, which ECCC combines into one record.
| Distance from the town | 14 km north-east |
| Station altitude | 140 m |
| Completeness | at least 20 years |
| WMO standard normals | No |
| Coldest reading, 1991–2020 | −28.0°C |
| Hottest reading, 1991–2020 | 37.1°C |
| Next-nearest location | Toronto Buttonville (Airport), 27 km |
How Ajax 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 Ajax’s would only repeat its figures.
| Town | July high | January low | Rain & snow |
|---|---|---|---|
| Ajax Oshawa | 25.7°C | −8.9°C | 906 mm |
| Pickering 6.6 km · Oshawa | 25.7°C about the same | −8.9°C about the same | 906 mm |
| West Rouge 12 km · Toronto Buttonville (Airport) | 27.3°C 1.6°C warmer | −10.1°C 1.2°C colder | 862 mm |
Ajax weather by month
Average daily high and low, mean temperature, rain and snow (as water) and snowfall by month, 1991–2020.
| Month | High | Low | Mean | Rain & snow | Snow |
|---|---|---|---|---|---|
| January | −1.1°C | −8.9°C | −5.0°C | 75 mm | 34 cm |
| February | −0.2°C | −8.3°C | −4.2°C | 54 mm | 26 cm |
| March | 4.5°C | −3.9°C | 0.3°C | 54 mm | 11 cm |
| April | 10.6°C | 1.7°C | 6.2°C | 87 mm | 2 cm |
| May | 17.5°C | 7.6°C | 12.6°C | 85 mm | 0 cm |
| June | 22.7°C | 12.9°C | 17.8°C | 94 mm | 0 cm |
| July | 25.7°C | 15.8°C | 20.9°C | 86 mm | 0 cm |
| August | 24.8°C | 15.4°C | 20.1°C | 74 mm | 0 cm |
| September | 20.9°C | 11.4°C | 16.2°C | 86 mm | 0 cm |
| October | 13.6°C | 5.3°C | 9.5°C | 72 mm | under 1 cm |
| November | 7.5°C | 0.3°C | 3.9°C | 73 mm | 5 cm |
| December | 2.2°C | −4.6°C | −1.2°C | 68 mm | 25 cm |
| Year | 12.4°C | 3.7°C | 8.1°C | 906 mm | 102 cm |
A March here can run from −25.2°C to 23.3°C
Bars run from each month’s record low to its record high over 1991–2020; February is the month whose average wanders most from year to year (±3.0°C around −4.2°C), October the one that wanders least (±0.9°C).
Where Ajax’s numbers come from
Averages over 30 years, not a forecast.
- Normals: the 1991–2020 Canadian Climate Normals at Oshawa, the closest ECCC location with twelve months of temperature normals.
- Comparisons: every place of 2,500+ in Canada but the city hubs and the reserves, each on its nearest ECCC location.
- Not on this page: hours of sunshine, missing from the 1991–2020 normals, and a height correction: the town has no elevation on file.
Canadian Climate Normals 1991–2020 · ECCC Data Services End-use Licence. Data Source: Environment and Climate Change Canada
Questions about Ajax’s climate
How warm does Ajax get in summer?
Expect highs near 25.7°C in July, the hottest month on average.
How cold does Ajax get in winter?
The coldest nights come in January, averaging −8.9°C.
How much rain and snow does Ajax get?
Over twelve months, rain and melted snow come to 906 mm; the range runs from 54 mm in February to 94 mm in June.
How long does snow stay on the ground?
About 55 days a year have 1 cm of snow or more on the ground.
Are these figures for Ajax itself?
They are the closest available: the normals for Oshawa, since Ajax has none.
Data Source: Environment and Climate Change Canada · ECCC Data Services End-use Licence Today’s forecast for Ajax →
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).