South Korea‘s rainy season, known as jangma, usually runs from late June into late July, but its timing differs across Jeju, the south and central Korea.
- Jeju has the earliest normal jangma window: 19 June to 20 July.
- Southern Korea, including Busan, normally sits in the 23 June to 24 July window.
- Central Korea, including Seoul, has the latest normal window: 25 June to 26 July.
- KMA’s current 2026 analysis places the jangma start on 30 June in Jeju and the south, and on 1 July in central Korea.
- Normal dates are 1991–2020 averages, not exact forecasts for an individual trip.
When is the South Korea rainy season?
KMA describes jangma as a period of frequent heavy rain associated with the rainy-season front, generally from late June to late July. The front does not affect every region on the same schedule.
Jeju normally enters jangma first, followed by southern Korea and then central Korea. That south-to-north sequence is useful for broad planning, but a single shower does not by itself define the official start or end of the season.
When jangma normally moves north
KMA 1991–2020 climate normals — planning ranges, not confirmed 2026 dates
| Normal window | 19 Jun–20 Jul |
|---|---|
| Normal duration | 32.4 days |
| Rain days | 17.5 days |
| Rainfall | 348.7 mm |
| Plan for | Keep trails and sea-facing activities flexible. Jeju normally enters and leaves jangma first; KMA’s current 2026 analysis places its onset later than the normal date. |
| Normal window | 23 Jun–24 Jul |
|---|---|
| Normal duration | 31.4 days |
| Rain days | 17.0 days |
| Rainfall | 341.1 mm |
| Plan for | Keep coastal walks and viewpoints movable. The southern normal window starts and ends two days before central Korea. |
| Normal window | 25 Jun–26 Jul |
|---|---|
| Normal duration | 31.5 days |
| Rain days | 17.7 days |
| Rainfall | 378.3 mm |
| Plan for | Keep indoor alternatives for city days and allow flexible timing for viewpoints. Central Korea has the latest normal end date of the three regions. |
Source: Korea Meteorological Administration rainy-season statistics. Dates, duration, rain days and rainfall are regional climate normals.
What does KMA currently report for Korea jangma 2026?
KMA’s current analysis places the 2026 rainy-season start on 30 June in Jeju and southern Korea. It places the central Korea start on 1 July.
These dates are preliminary planning references. Final start and end dates follow KMA’s retrospective seasonal analysis and may differ from current reporting.
The Jeju start was 11 days later than its normal date, while the southern start was seven days later than normal. KMA linked the delay to atmospheric blocking and a delayed expansion of the North Pacific high-pressure system.
No normal end date should be presented as a confirmed 2026 end date. Travelers should treat KMA’s daily forecasts and warning status as the current source of truth because conditions can differ by place and day.
How to plan a South Korea rainy-season trip
A rainy-season trip can still work well when the itinerary has room to move. Use the following checklist before and during travel.
- Check the official forecast daily. KMA updates short-range forecasts, warning status and radar information as conditions change.
- Keep one indoor alternative. Pair each exposed viewpoint, trail or coastal stop with a museum, market or other sheltered activity nearby.
- Allow extra transfer time on rainy days, and avoid tight connections between separate bookings.
- Pack quick-drying clothes, a compact umbrella, a light waterproof layer and a water-resistant pouch for electronics.
- Follow warnings. If KMA issues severe-weather advice, change the plan and follow local instructions rather than relying on a seasonal average.
Planning flights and hotels by region
Start by comparing routes, then keep weather-sensitive activities movable within each stop. For the capital, choose from Seoul hotels near the activities you most want to keep.
In the south, browse Busan hotels. For an island stay, compare Jeju hotels with enough flexibility to rearrange outdoor days.
Frequently Asked Questions
When is the South Korea rainy season in 2026?
KMA’s current analysis places the 2026 jangma start on 30 June for Jeju and southern Korea, and on 1 July for central Korea. Final start and end dates follow retrospective seasonal analysis and may differ; do not use the climate-normal calendar as a confirmed 2026 endpoint.
Does it rain every day during jangma?
No seasonal average can tell you whether it will rain every day of a specific trip. KMA’s normals show roughly 17 to 17.7 rain days during the regional jangma period, so dry intervals are possible even while the season is active.
Is Seoul’s rainy season later than Jeju’s?
Yes, according to KMA’s 1991–2020 normals. Jeju’s normal window begins on 19 June, while the central region containing Seoul begins on 25 June.
Should I cancel a South Korea trip because of jangma?
A climate normal alone is not a reason to cancel. Check the live forecast and warnings, keep outdoor plans flexible and change your route if official advice indicates unsafe conditions.
Sources
- Korea Meteorological Administration — Rainy-season statistics and 1991–2020 normals
- Korea Meteorological Administration — June 2026 climate characteristics and jangma onset
- Korea Meteorological Administration — Current severe-weather warnings and safety information
Disclaimer: We’ve worked hard to make sure the information in this article is as accurate and up to date as possible at the time of publishing. Travel details such as prices, schedules, visa rules, and entry requirements can change at short notice, so it remains your responsibility to verify the current details with official sources before you book or travel. Wego accepts no liability for any loss or inconvenience arising from the use of this content.
