2026-07-18 Heavy Rain in Central South Korea: When Will It Be Heaviest in Seoul, Gyeonggi and Chungcheong?
이 포스팅은 쿠팡 파트너스 활동의 일환으로, 이에 따른 일정액의 수수료를 제공받습니다.
This article is based on the latest available news reports and official information verified as of 2026-07-18 Korea Standard Time.
As of 3:44 a.m. on 2026-07-18, the period when rainfall is most likely to be heaviest in central South Korea is between 3 a.m. and noon.
Parts of the Seoul metropolitan area, northern South Chungcheong Province, central and northern North Chungcheong Province, and inland and mountainous areas of Gangwon Province are forecast to receive extremely heavy rainfall of 50–80mm per hour. If you plan to travel on Saturday morning or have outdoor activities scheduled, do not rely solely on the probability of precipitation. Check both weather radar and road closure information immediately before departure.
The key concern is that this rainfall is more likely to arrive in short, intense bursts than to fall evenly throughout the day.
When Heavy Rain Is Expected in Each Region
The following table converts the information released by the Korea Meteorological Administration (KMA) on the night of July 17 into the actual times for 18.
| Region | Period When Heavy Rain Is Most Likely | Expected Hourly Rainfall Intensity |
|---|---|---|
| Seoul, Incheon and northern Gyeonggi | 18, 03–09 | Up to 50–80mm |
| Southern Gyeonggi | 18, 03–12 | Up to 50–80mm |
| Northern South Chungcheong | 18, 03–12 | Up to 50–80mm |
| Central and northern North Chungcheong | 18, 06–12 | Up to 50–80mm |
| Inland and mountainous areas of central and southern Gangwon | 18, 06–12 | Up to 50–80mm |
| Inland and mountainous areas of northern Gangwon | 18, 03–12 | Up to 30–50mm |
The areas experiencing the heaviest rainfall may change depending on the location and development of rain clouds. Rainfall totals can vary considerably between neighborhoods within the same city or county. Checking very-short-range precipitation forecasts for your current location is therefore more accurate than relying on a nationwide forecast.
How Much Rain Is Expected From 18 to 19?
According to the KMA's short-range forecast, the following cumulative rainfall totals are expected from 18 through 19.
Seoul, Incheon and Gyeonggi: 100–200mm, with 300mm or more in some areas
Gangwon Province: 100–200mm, with 300mm or more in some inland and mountainous areas of central and southern Gangwon
Daejeon, Sejong, South Chungcheong and North Chungcheong: 80–150mm, with 250mm or more in some areas
Central and northern North Gyeongsang: 50–100mm, with 150mm or more in some areas
Western North Jeolla: 30–100mm; Gwangju and South Jeolla, as well as Busan, Ulsan and South Gyeongsang: 20–60mm
The higher rainfall figures described as occurring 'in some areas' do not apply uniformly to every location. They should be understood as the upper range that may occur in relatively narrow areas repeatedly affected by intense rain bands.
Will It Be Safe Once the Morning Has Passed?
Although the early morning and morning hours have been identified as the most dangerous period, this does not mean the rain will stop completely after noon.
The Seoul metropolitan area and Chungcheong region may experience another round of heavy rainfall from late afternoon through the night on 18. Rainfall intensity may also increase again in parts of North Chungcheong, North Jeolla and North Gyeongsang between the night of 18 and the early morning of 19.
Even if the rain weakens during the morning, restrictions on riverside areas and underpasses may remain in place until water levels fall and conditions are safe. Never cross barriers or enter restricted areas.
Four Things to Check Before Traveling This Weekend
Immediately before departure, it is advisable to check the following four items in order.
1. Check the current location and direction of movement of rain clouds using KMA weather radar.
2. Check whether a heavy rain advisory or heavy rain warning is in effect in your area.
3. Review your navigation route to see whether it includes underpasses, low-water crossings or roads alongside rivers.
4. In Seoul, check TOPIS and police traffic information to confirm whether any roads are actually closed.
Even if buses and subways are operating normally, flooding and infrastructure inspections may cause detours or delays. If you plan to travel by train, airplane or passenger ferry, it is safer to check announcements from the relevant operator before departure.
What Should You Do If Water Starts Accumulating on the Road While Driving?
The first priority is to avoid entering underpasses and low-lying roads where it is difficult to determine the depth of the water.
Just because the vehicle ahead has passed through a flooded section does not mean your vehicle can cross safely. Conditions may differ depending on vehicle height, water flow and road gradient.
If you have already entered a flooded section or your vehicle can no longer move, prioritize your safety over protecting the vehicle. Move quickly to nearby higher ground and report the emergency to 119.
Water levels along riverside walking paths and in valleys can also rise rapidly because of water flowing downstream from upstream areas, even when the rain appears to have temporarily stopped. Camping or water-related recreational activities should be canceled or moved to another location, even if the weather at the site appears acceptable.
When Should You Check the Forecast Again?
This article was prepared based on the KMA announcement issued at 22:20 on July 17.
KMA weather briefings may typically be updated around 4 a.m., 10 a.m., 4 p.m. and 10 p.m. If you plan to travel on the morning of July 18, check the updated information released after 4 a.m.
On July 18, people in central South Korea should prepare for short periods of intense rainfall from the early morning through the morning hours. Decisions about whether to travel should be based on the latest weather radar and road closure information immediately before departure.
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이 포스팅은 쿠팡 파트너스 활동의 일환으로, 이에 따른 일정액의 수수료를 제공받습니다.