Mild
Average highs are around 21°C, so days are mild rather than hot.
September verdict
Seattle, Washington, United States in September
Weather score48Mixed
Mixed for holiday weather
Average highs are around 21°C, so days are mild rather than hot. Sunshine averages 7.1h per day, enough for a balanced month. Rainfall averages 49mm, which is relatively low for holiday planning.
September weather
Monthly averages
Temp
21°C
Rain
49mm
Sun
7.1h
Sea
11°C
Weather score
48
Mixed
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
SwimSwim
Weather scoreWeather score
Trip feel
Drier
Rainfall averages 49mm, which is relatively low for holiday planning.
Some sun
Sunshine averages 7.1h per day, enough for a balanced month.
Cool sea
Sea temperatures average 11°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
September21°C average high
September sits in the warmer part of the year, so midday sightseeing can feel heavier than in cooler months.
Warmest monthsJune to September
This stretch sets the upper range for average daytime heat.
Rain
September49mm average rain
September sits on the drier side of Seattle's year, which helps with sightseeing and transfers.
Driest monthsApril to September
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
September7.1 hours average sun
September sits close to Seattle's yearly sunshine average, so it is a middle-of-the-pack month for bright days.
Brightest monthsMay to August
This stretch has the strongest sunshine in the monthly averages.
Sea temperature
September11°C average sea
September sits in the warmer sea-temperature season, usually making swimming easier to enjoy.
Warmest seaJune to September
Sea temperatures are usually near 11°C in this stretch, so swimming comfort is at its strongest.
Weather score
September48 weather score
September scores above Seattle's yearly average, so the overall weather mix is stronger than most months.
Best weather monthsJune to August
These months have the strongest weather score in the monthly averages.
