Climate averages 1991–2020
Nepean weather
in December.
A freezing month with moderate precipitation: the 10th warmest and the 4th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a freezing month in Nepean: daytime highs average -1.1°C and nights cool to about -8.4°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 76 mm of precipitation on roughly 12 days, which makes December a month with moderate precipitation (the 4th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 8 h 48 min on an average December day.
The nearest other city in this atlas is Gloucester, Canada (7 km away). In December its highs average -1.3°C, about as warm as Nepean, with 76 mm of precipitation.
Among the 86 cities listed in Canada, Nepean ranks joint 55th of 86 for the warmest December highs and joint 44th of 86 for the driest December (precipitation, lowest first). The mean December high of those 86 cities is 0.2°C; Nepean is 1.3°C cooler than that mean.
From December to January, average highs fall by 3.8°C to -4.8°C, and monthly precipitation falls from 76 mm to 70 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
Nepean climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -4.8°C-14.6°C | -14.6°C | 70 | 10.4 | 9.29 h |
| February | -3.0°C-13.4°C | -13.4°C | 57 | 8.9 | 10.410 h |
| March | 2.7°C-7.5°C | -7.5°C | 71 | 10.2 | 11.912 h |
| April | 10.7°C0.3°C | 0.3°C | 92 | 11.3 | 13.513 h |
| May | 18.4°C7.7°C | 7.7°C | 85 | 11.3 | 14.915 h |
| June | 23.3°C13.3°C | 13.3°C | 95 | 11.3 | 15.616 h |
| July | 25.7°C16.3°C | 16.3°C | 94 | 11.7 | 15.315 h |
| August | 24.5°C15.7°C | 15.7°C | 86 | 10.8 | 14.114 h |
| September | 20.4°C11.8°C | 11.8°C | 90 | 9.9 | 12.613 h |
| October | 12.8°C5.4°C | 5.4°C | 97 | 11.7 | 11.011 h |
| November | 5.5°C-1.0°C | -1.0°C | 80 | 11.1 | 9.610 h |
| December, selected | -1.1°C-8.4°C | -8.4°C | 76 | 11.5 | 8.89 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
- Gloucester, Canada in DecemberCanada · 7 kmHigh -1.3°C · Low -8.5°C · 76 mm precipitation
- Ottawa in DecemberCanada · 9 kmHigh -1.1°C · Low -7.9°C · 79 mm precipitation
- Kanata in DecemberCanada · 16 kmHigh -1.1°C · Low -8.5°C · 74 mm precipitation
- Gatineau in DecemberCanada · 16 kmHigh -1.2°C · Low -8.4°C · 79 mm precipitation
- Orléans, Canada in DecemberCanada · 22 kmHigh -1.5°C · Low -8.6°C · 80 mm precipitation
- Kingston, Canada in DecemberCanada · 137 kmHigh 1.2°C · Low -4.0°C · 83 mm precipitation
- Pierrefonds-Roxboro in DecemberCanada · 148 kmHigh -1.2°C · Low -7.8°C · 85 mm precipitation
- Saint-Louis-de-Terrebonne in DecemberCanada · 156 kmHigh -1.9°C · Low -9.6°C · 86 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 Nepean) is explained once on the Nepean year overview and on the Sources, method and limits page.
Gloucester, Canada lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.