In December, Portland typically sees daytime highs of 1.0°C and overnight lows around -7.0°C. Compared to the annual average high of 12.6°C, December runs -11.6°C.
December in Portland averages a daytime high of 1.0°C and an overnight low of -7.0°C.
December runs -11.6°C compared to Portland's annual average high of 12.6°C, ranking #10 of 12 months by warmth.
Plan for daytime highs near 1.0°C and cooler evenings around -7.0°C.