Cool
Average highs are around 8°C, so pack for cooler days.
December verdict
Seattle, Washington, United States in December
Weather score11Poor
Poor for holiday weather
Average highs are around 8°C, so pack for cooler days. Sunshine averages 1.7h per day, so this is not one of the brighter months. Rainfall averages 151mm, so some wet days are possible.
December weather
Monthly averages
Temp
8°C
Rain
151mm
Sun
1.7h
Sea
9°C
Weather score
11
Poor
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
SwimSwim
Weather scoreWeather score
Trip feel
Showers
Rainfall averages 151mm, so some wet days are possible.
Limited sun
Sunshine averages 1.7h per day, so this is not one of the brighter months.
Cool sea
Sea temperatures average 9°C, so the water can feel cool.
Map
Weather map
Compare Seattle, Washington, United States with nearby places by weather score, rain, sun, temperature, and swim conditions.
Temperature
December8°C average high
December has some of the coolest average daytime highs of the year, so pack for fresher conditions.
Warmest monthsJune to September
This stretch sets the upper range for average daytime heat.
Rain
December151mm average rain
December is one of Seattle's wettest months, so rain is likely to be a major planning factor.
Driest monthsApril to September
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
December1.7 hours average sun
December is one of Seattle's cloudier months, so sunshine-led plans are less reliable.
Brightest monthsMay to August
This stretch has the strongest sunshine in the monthly averages.
Sea temperature
December9°C average sea
December is below Seattle's yearly sea-temperature average, so swimming can feel fresher.
Warmest seaJune to September
Sea temperatures are usually near 11°C in this stretch, so swimming comfort is at its strongest.
Weather score
December11 weather score
December is one of the weakest weather-score months, when the overall mix is less favourable than the rest of the year.
Best weather monthsJune to August
These months have the strongest weather score in the monthly averages.
