Seoul Weather by Month: Temperatures, Rain and What to Pack

Seoul is hottest in August, with an average high of 30.0°C and a low of 22.9°C, and coldest in January, when the high sits near 2.1°C and the low at -5.5°C. July is the wettest month at 414.4 mm. The table below has every month, and each season gets a few lines on what the numbers mean for a trip.

Seoul weather by month

The figures are the Korea Meteorological Administration’s normals for the Seoul station, averaged over 1991 to 2020 (KMA climate normals). Highs and lows are the means of the daily maximum and minimum, and rain is the mean monthly total.

Month	Average high	Average low	Rain
January	2.1°C	-5.5°C	16.8 mm
February	5.1°C	-3.2°C	28.2 mm
March	11.0°C	1.9°C	36.9 mm
April	17.9°C	8.0°C	72.9 mm
May	23.6°C	13.5°C	103.6 mm
June	27.6°C	18.7°C	129.5 mm
July	29.0°C	22.3°C	414.4 mm
August	30.0°C	22.9°C	348.2 mm
September	26.2°C	17.7°C	141.5 mm
October	20.2°C	10.6°C	52.2 mm
November	11.9°C	3.5°C	51.1 mm
December	4.2°C	-3.4°C	22.6 mm

These are averages. A single week can run several degrees either side, so pack for the range in the table and check the forecast before you travel. Don’t plan around one number.

Seoul weather in winter: December to February

Winter is cold and dry. Highs stay between 2.1°C and 5.1°C, and the average low is below freezing in all three months, from -3.4°C in December to -5.5°C in January. January also has the least rain in the table, 16.8 mm. Pack a heavy coat, gloves and a warm layer, and you’ll likely spend the coldest days moving between indoor stops.

Seoul weather in March and April

March is still cold at night, with a 1.9°C average low, and the high reaches 11.0°C. April warms to 17.9°C by day and 8.0°C at night, with rain rising to 72.9 mm. You’ll want a coat in the morning and a lighter layer for the afternoon, and that covers both months.

Seoul weather in May and June

May has a 23.6°C high and a 13.5°C low, with 103.6 mm of rain. June is warmer at 27.6°C by day and 18.7°C at night, and rain climbs to 129.5 mm. Both months are easy for a full day outside, with a light jacket for May evenings.

Seoul weather in July and August

These are the wettest months by a wide margin. July has 414.4 mm and August 348.2 mm, together about 762.6 mm of the year’s 1,417.9 mm, more than half. July has a 29.0°C high and a 22.3°C low, and August is the hottest month at 30.0°C and 22.9°C. Nights stay above 22°C in both, so it doesn’t cool off much after dark. Bring a rain jacket and plan indoor stops for the afternoons.

Seoul weather in September and October

September is still warm at 26.2°C by day and 17.7°C at night, but rain falls to 141.5 mm. October cools to 20.2°C by day and 10.6°C at night, with just 52.2 mm of rain, one of the drier months of the year. A light jacket is enough, and it’s worth having for mornings and evenings.

Seoul weather in November

November has an 11.9°C high and a 3.5°C low, with 51.1 mm of rain. The nights are close to freezing, so you’ll want a proper coat and a warm layer.

Which month has the best weather?

The comfortable stretches are April to May and October, when average highs sit between about 18°C and 24°C and rain is lower than in summer. October has the least rain of the three, at 52.2 mm.

Planning around the weather

Use the map to find indoor places for wet days, and events for what is on the dates you travel.
The Seoul travel tips page covers practical points for the trip, and things to do in Seoul lists what to plan around the forecast.
The where to stay in Seoul guide compares the areas, where to eat in Seoul covers meals, and best day trips from Seoul helps if you want to leave the city.