Korea in July 2027: Rainy Season, Heat and the Mud Festival

Source: KMA climate normals 1991–2020, stations 108, 159 and 184 (KMA). Seoul's July average is 25.3°C, and its average relative humidity is 76.2%.

These are 30-year averages, not a forecast. Seoul's 414.4 mm is about 29% of its annual 1,417.9 mm. Much of it falls on a few days of heavy rain, so a single trip can be dry or soaked. Check the KMA forecast in the week before you fly.

The rainy season, 장마jangmaRainy season, normally starts around 19 June on Jeju, 23 June in the south and 25 June in Seoul, and lasts about 31 days on the mainland and about 32 days on Jeju (KMA). So in a normal year it runs through most of July. The Korea Tourism Organization advises visitors from late June to late July to check the forecast (VisitKorea).

Typhoons, 태풍taepungTyphoon, are possible from June to October (KTO). KMA's 1991–2020 normal for July is 3.7 typhoons forming in the North Pacific and 1.0 affecting Korea (KMA). If a typhoon is forecast, flights and ferries to islands can be cancelled and outdoor events postponed. Check the KMA forecast daily, and read the safety guide.

Hot days are called 폭염pokyeomHeat wave in Korean. From June 2026, KMA uses these thresholds, based on the "feels like" temperature (KMA):

KMA's tropical night advisory applies only in areas already under a heat wave advisory or higher. These systems are new in 2026, so check KMA's current page for the exact rules.

The traditional hottest days, the 삼복sambokThree hottest days, are 초복ChobokFirst hot day on 20 July and 중복JungbokMiddle hot day on 30 July 2027 (KASI). They are not holidays. The last one, 말복MalbokLast hot day, is on 9 August.

• Light, breathable clothes. The KTO recommends breathable clothing, sun protection products, and an umbrella or raincoat for summer.
• A rain jacket or compact umbrella. Carry one every day.
• Quick-drying shoes. Streets can hold standing water after heavy rain.
• A thin layer. Subways, malls and cafés use strong air conditioning.
• A water bottle. Plan indoor stops, such as museums and markets, for the hottest hours.

Source: KASI calendar data 2027. Constitution Day was reinstated as a public holiday from 2026 (VisitKorea). In 2027 it falls on a Saturday, which gives a three-day weekend with the Monday substitute. Banks and government offices close.

No organizer had published 2027 dates when this page was written. These are the 2026 dates, to show the usual timing.

Sources: VisitKorea and Seoul Metropolitan Government. The Mud Festival's official site is mudfestival.or.kr; check it for ticket rules, because some programs may charge admission. The Seoul pools' 2026 prices were 5,000 won for adults and 3,000 won for children aged 6–12. The 2027 dates for both events are not announced. For other events, see the Korea Tourism Organization's festival listings.

The Korea Tourism Organization names July to August and December to January as peak seasons, when flight prices rise (VisitKorea). Many stores hold sales from June to August (VisitKorea). Book rooms and long-distance trains early, especially for coast trips on weekends.

• Seoul: museums, markets and covered shopping streets for wet days. See the Seoul guide.
• Busan: the beaches are open, but Busan gets 326.8 mm of rain in July. See the Busan guide.
• Jeju: warm and humid, with 210.2 mm of rain. See the Jeju guide.