Mild
Average highs are around 25°C, so days are mild rather than hot.
September verdict
Jeju-do, South Korea in September
Weather score64Good
Good for holiday weather
Average highs are around 25°C, so days are mild rather than hot. Sunshine averages 6.4h per day, enough for a balanced month. Rainfall averages 153mm, so some wet days are possible.
September weather
Monthly averages
Temp
25°C
Rain
153mm
Sun
6.4h
Sea
26°C
Weather score
64
Good
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
SwimSwim
Weather scoreWeather score
Trip feel
Showers
Rainfall averages 153mm, so some wet days are possible.
Some sun
Sunshine averages 6.4h per day, enough for a balanced month.
Swimmable
Sea temperatures average 26°C, which can work for swimming but may feel fresh.
Map
Weather map
Compare Jeju-do, South Korea with nearby places by weather score, rain, sun, temperature, and swim conditions.
Temperature
September25°C average high
September sits in the warmer part of the year, so midday sightseeing can feel heavier than in cooler months.
Warmest monthsJuly to September
This stretch sets the upper range for average daytime heat.
Rain
September153mm average rain
September sits near Jeju-do's yearly rainfall average, so rain is a normal planning factor rather than an outlier.
Driest monthsJanuary to March and October to December
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
September6.4 hours average sun
September is brighter than Jeju-do's yearly average, though the strongest sunshine usually sits closer to the peak months.
Brightest monthsMay and August
This stretch has the strongest sunshine in the monthly averages.
Sea temperature
September26°C average sea
September sits in the warmer sea-temperature season, usually making swimming easier to enjoy.
Warmest seaJuly to September
Sea temperatures are usually near 25°C in this stretch, so swimming comfort is at its strongest.
Weather score
September64 weather score
September is one of Jeju-do's best weather-score months, combining the strongest overall balance in the yearly averages.
Best weather monthsJuly to October
These months have the strongest weather score in the monthly averages.
