In December, Sammamish typically sees daytime highs of 7.5°C and overnight lows around 2.5°C. Compared to the annual average high of 15.1°C, December runs -7.6°C.
December in Sammamish averages a daytime high of 7.5°C and an overnight low of 2.5°C.
December runs -7.6°C compared to Sammamish's annual average high of 15.1°C, ranking #11 of 12 months by warmth.
Plan for daytime highs near 7.5°C and cooler evenings around 2.5°C.