Koch'ang in Summer
In summer (June, July and August), Koch'ang sees average daytime highs around 28°C and overnight lows near 21°C, with 613 mm of rain over about 41 wet days across the season. It is the warmest season of the year and the wettest season of the year.
Over the season highs climb from about 25°C in early June to 28°C by late August. The sky is clear or mostly clear about 24% of the time across summer, and the air most often feels oppressive.
Summer is Koch'ang's 3rd-best season to visit on our travel score. For the whole year in context, see Koch'ang's year-round climate.
- Avg daytime high
- 28°C
- warmest season of the year
- Avg overnight low
- 21°C
- Rainfall
- 613 mm
- 41 wet days
- Avg wind
- 9 km/h
- Travel score
- 5.4
- 3rd-best season
- Months
- Jun · Jul · Aug
Temperature in Koch'ang in Summer
Over the season highs climb from about 25°C in early June to 28°C by late August.
A typical summer day in Koch'ang reaches about 28°C and drops to 21°C overnight. The warmest of the three months is August, the coolest June.
How summer really feels in Koch'ang
Once humidity and wind are folded in, summer brings about 34 days that feel above 32°C and 0 that feel at or below 0°C.
The story in summer is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Koch'ang weather by month
How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 4° / -3° | 28 | 5.9 | 4.1 | 9.9 | 0.0 |
| Feb | 6° / -2° | 33 | 5.4 | 1.7 | 10.7 | 0.7 |
| Mar | 11° / 2° | 55 | 7.3 | 1 | 11.7 | 3.2 |
| Apr | 17° / 7° | 81 | 7.5 | 0 | 12.9 | 5.9 |
| May | 22° / 13° | 88 | 7.8 | 0 | 13.8 | 7.1 |
| Jun | 26° / 18° | 147 | 9.6 | 0 | 14.3 | 6.6 |
| Jul | 29° / 23° | 238 | 15.6 | 0 | 14.1 | 4.9 |
| Aug | 29° / 23° | 228 | 16 | 0 | 13.3 | 4.6 |
| Sep | 26° / 18° | 150 | 9.5 | 0 | 12.2 | 6.8 |
| Oct | 20° / 11° | 57 | 5.5 | 0 | 11.1 | 7.3 |
| Nov | 14° / 5° | 47 | 6.9 | 0.2 | 10.1 | 4.2 |
| Dec | 7° / -1° | 31 | 6.5 | 2.9 | 9.7 | 0.9 |
Cloud cover in Summer
The sky is clear or mostly clear about 24% of the time across summer.
Chance of precipitation in Summer
Koch'ang gets around 613 mm of rain over 41 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 9 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 h 12 min in early June to 12 h 48 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 5.1 kWh/m².
Hazard calendar for Koch'ang
In summer, Koch'ang overlaps its pacific typhoon and rainy season season. The full year is below, with each hazard's peak months called out.
Koch'ang sits in the Pacific typhoon belt; the season peaks July–October.
Koch'ang's rainy season runs June–September, when most of the year's rain falls.
Is summer a good time to visit Koch'ang?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit Koch'ang for sightseeing.
What to pack for Koch'ang in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Koch'ang sees daytime highs around 28°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 41 days see rain.
Sea temperature near Koch'ang in Summer
The nearest coast averages about 22°C across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 30 km away) is warmest in August at about 25°C and coldest in February near 6°C.
It's comfortable for a long swim from Jun 26 to Oct 11 — about 3.6 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 8 | 6 | 7 | 10 | 14 | 19 | 23 | 25 | 23 | 19 | 15 | 11 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Cool | Refreshing | Warm | Refreshing | Cool | Cool | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 8 | Bracing |
| Feb | 6 | Bracing |
| Mar | 7 | Bracing |
| Apr | 10 | Bracing |
| May | 14 | Bracing |
| Jun | 19 | Cool |
| Jul | 23 | Refreshing |
| Aug | 25 | Warm |
| Sep | 23 | Refreshing |
| Oct | 19 | Cool |
| Nov | 15 | Cool |
| Dec | 11 | Bracing |
UV index in Koch'ang in Summer
Clear-sky midday UV across summer averages around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Koch'ang peaks around September 12 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 2 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 3 | 5 | 7 | 7 | 8 | 8 | 7 | 8 | 5 | 4 | 2 |
| Level | Moderate | Moderate | High | High | Very high | Very high | Very high | Very high | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Moderate |
| Feb | 3 | Moderate |
| Mar | 5 | High |
| Apr | 7 | High |
| May | 7 | Very high |
| Jun | 8 | Very high |
| Jul | 8 | Very high |
| Aug | 7 | Very high |
| Sep | 8 | Very high |
| Oct | 5 | High |
| Nov | 4 | Moderate |
| Dec | 2 | Moderate |
Air quality in Koch'ang in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.
Air quality in Koch'ang is worst in March — around 61 µg/m³ PM2.5 (unhealthy), about 2.1× the cleanest month (August, 28 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 41 | 48 | 61 | 54 | 45 | 39 | 29 | 28 | 33 | 35 | 38 | 34 |
| Level | Poor | Poor | Unhealthy | Poor | Poor | Poor | Moderate | Moderate | Moderate | Moderate | Poor | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 41 | Poor |
| Feb | 48 | Poor |
| Mar | 61 | Unhealthy |
| Apr | 54 | Poor |
| May | 45 | Poor |
| Jun | 39 | Poor |
| Jul | 29 | Moderate |
| Aug | 28 | Moderate |
| Sep | 33 | Moderate |
| Oct | 35 | Moderate |
| Nov | 38 | Poor |
| Dec | 34 | Moderate |
Where is Koch'ang?
Koch'ang sits at 35.4°N, 126.7°E, 44 m above sea level, in South Korea. The nearest listed city is Jangseong, 17 km away.
Topography around Koch'ang
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Koch'ang.
Within 3 km, the terrain around Koch'ang has significant variations in elevation — a maximum elevation change of 403 m around an average of 91 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 730 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,720 m.
The land around Koch'ang is covered by trees (48%) and cropland (29%) within 3 km, trees (57%) and cropland (31%) within 16 km, and trees (40%), water (34%) and cropland (21%) within 80 km.
South Korea travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type C / F
- 220 V · 60 Hz
- Prices
- ≈ 57% of US
- price level, 2025
- GDP per capita
- $36,227
- 2025
- Happiness
- 6.0 / 10
- World Happiness, 2025
- Safe drinking water
- 99%
- of population, 2024
- Homicide rate
- 0.5
- per 100k, 2023
- Road deaths
- 8.6
- per 100k/yr, 2019
- Income group
- High
- World Bank
- English
- Moderate
- EF EPI 522
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Koch'ang (35.4333°, 126.7°, elevation 44 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.