Seoul weather in May
In May, Seoul has an average high of 21 °C70 °F and an average low of 11 °C52 °F, with about 84 mm3.3 in of precipitation. It is the 5th warmest month of the year and ranks 5th for precipitation.
How May compares with other months
Compared with April, May is 6.1 °C10.9 °F warmer on average and wetter by 12 mm0.5 in. Compared with June, May is 5 °C9 °F cooler on average and drier by 32 mm1.3 in. Daylight lasts about 14.2 hours around the middle of the month. Average relative humidity is 75% and the average cloud amount 56%.
Is May a good time to visit Seoul?
Yes — May is one of the most comfortable months to visit Seoul by our comfort score, which favours average highs of 21–28 °C, lows above 5 °C, little rain and moderate humidity.
What to wear in May
For Seoul in May, pack light layers — T-shirts plus a light sweater or jacket and an extra layer for the cooler mornings and evenings.
May in nearby places
Other months in Seoul
- January1 °C33 °F / −7 °C20 °F
- February3 °C38 °F / −5 °C23 °F
- March9 °C48 °F / −1 °C30 °F
- April15 °C60 °F / 5 °C40 °F
- May21 °C70 °F / 11 °C52 °F
- June26 °C78 °F / 17 °C62 °F
- July28 °C82 °F / 21 °C70 °F
- August28 °C83 °F / 22 °C71 °F
- September25 °C76 °F / 17 °C62 °F
- October19 °C65 °F / 10 °C49 °F
- November11 °C51 °F / 3 °C37 °F
- December3 °C37 °F / −4 °C24 °F
Frequently asked questions
How warm is Seoul in May?
In May the average high in Seoul is 21 °C (70 °F) and the average low is 11 °C (52 °F).
Does it rain a lot in Seoul in May?
On average about 84 mm (3.3 in) of precipitation falls in May; it ranks 5th of the 12 months.
Is May the warmest month in Seoul?
No. The warmest month in Seoul is August, with an average high of 28 °C (83 °F). The coldest month is January, with an average low of -7 °C (20 °F).
How long is the day in Seoul in May?
In the middle of May the day in Seoul lasts about 14.2 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Seoul in May?
The average relative humidity in May is about 75%. This is a long-term average for the whole day.
How cloudy is Seoul in May?
On average about 56% of the sky is covered by cloud in May. This is the mean cloud amount from satellite data, not the number of sunny days.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.