In December, Ottawa typically sees daytime highs of -3.3°C and overnight lows around -12.0°C. Compared to the annual average high of 11.1°C, December runs -14.3°C.
December in Ottawa averages a daytime high of -3.3°C and an overnight low of -12.0°C.
December runs -14.3°C compared to Ottawa's annual average high of 11.1°C, ranking #10 of 12 months by warmth.
Plan for daytime highs near -3.3°C and cooler evenings around -12.0°C.