Ottawa is typically cold in December.

Maximum temperatures go down compared to the previous month from +43°F to +30°F. The minimum temperature also goes down from +28°F to +16°F.

Wear your winter warms as it will be cold. To save space, layer, and don’t forget gloves and a scarf.

December is one of the coolest months in Ottawa, here is the comparison with other months:

December weather is still as ok as in November. It’s getting colder in December. From +43°F in the day, the average maximum temperature lowers to +30°F. As December arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 54 mm to 24 mm. Humidity rises from 76% to 78%. The average wind speed doesn’t change much during December, staying around 3 m/s. The amount of sunny days stay about the same, averaging 2 sunny days during the month.

January brings much the same weather, it remains ok.

December is one of the snowiest months in Ottawa.

Here’s how December is compared with other months in the amount of snow, total mm:

The climate in Ottawa in December has not changed that much over the last 43 years.

The average temperature was the lowest in 1992 (+51°F) and the highest in 2024 (+57°F). The driest year was 1985 with only 469 mm of rainfall, and the wettest year was 2017 with 1378 mm.

For this page, we’ve looked at the typical weather in Ottawa, based on historical hourly weather data from January 1, 1979, to December 31, 2023.

For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.