Climate averages 1991–2020
Ajax weather
in December.
A cold month with moderate precipitation: the 10th warmest and the 9th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a cold month in Ajax: daytime highs average 1.7°C and nights cool to about -4.0°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 87 mm of precipitation on roughly 13 days, which makes December a month with moderate precipitation (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 8 h 59 min on an average December day.
The nearest other city in this atlas is Whitby (9 km away). In December its highs average 1.8°C, about as warm as Ajax, with 65 mm of precipitation.
Among the 86 cities listed in Canada, Ajax ranks joint 32nd of 86 for the warmest December highs and 64th of 86 for the driest December (precipitation, lowest first). The mean December high of those 86 cities is 0.2°C; Ajax is 1.5°C warmer than that mean.
From December to January, average highs fall by 3.2°C to -1.5°C, and monthly precipitation falls from 87 mm to 86 mm.
The annual picture
December in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Ajax climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -1.5°C-8.8°C | -8.8°C | 86 | 12.5 | 9.39 h |
| February | -1.0°C-9.1°C | -9.1°C | 61 | 9.1 | 10.410 h |
| March | 3.5°C-4.3°C | -4.3°C | 70 | 10.1 | 11.912 h |
| April | 10.0°C2.2°C | 2.2°C | 96 | 11.0 | 13.413 h |
| May | 16.5°C8.8°C | 8.8°C | 78 | 10.1 | 14.715 h |
| June | 22.1°C14.8°C | 14.8°C | 76 | 9.7 | 15.415 h |
| July | 25.4°C18.1°C | 18.1°C | 67 | 8.9 | 15.115 h |
| August | 24.8°C17.9°C | 17.9°C | 67 | 8.8 | 14.014 h |
| September | 21.0°C14.3°C | 14.3°C | 85 | 9.1 | 12.613 h |
| October | 14.0°C8.1°C | 8.1°C | 95 | 12.1 | 11.111 h |
| November | 7.2°C1.7°C | 1.7°C | 92 | 11.4 | 9.710 h |
| December, selected | 1.7°C-4.0°C | -4.0°C | 87 | 12.7 | 9.09 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Whitby in DecemberCanada · 9 kmHigh 1.8°C · Low -3.8°C · 65 mm precipitation
- Pickering in DecemberCanada · 10 kmHigh 1.0°C · Low -4.9°C · 62 mm precipitation
- Oshawa in DecemberCanada · 16 kmHigh 1.8°C · Low -3.8°C · 67 mm precipitation
- Markham in DecemberCanada · 19 kmHigh 1.5°C · Low -4.8°C · 81 mm precipitation
- Thornhill in DecemberCanada · 32 kmHigh 1.7°C · Low -4.0°C · 61 mm precipitation
- Richmond Hill in DecemberCanada · 33 kmHigh 1.1°C · Low -5.3°C · 61 mm precipitation
- Toronto in DecemberCanada · 33 kmHigh 1.9°C · Low -3.4°C · 61 mm precipitation
- Vaughan in DecemberCanada · 37 kmHigh 1.3°C · Low -4.8°C · 61 mm precipitation
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Ajax) is explained once on the Ajax year overview and on the Sources, method and limits page.