Seosan in Summer
In summer (June, July and August), Seosan sees average daytime highs around 27°C and overnight lows near 21°C, with 586 mm of rain over about 36 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 24°C in early June to 27°C by late August. The sky is clear or mostly clear about 28% of the time across summer, and the air most often feels oppressive.
Summer is Seosan's 2nd-best season to visit on our travel score. For the whole year in context, see Seosan's year-round climate.
- Avg daytime high
- 27°C
- warmest season of the year
- Avg overnight low
- 21°C
- Rainfall
- 586 mm
- 36 wet days
- Avg wind
- 11 km/h
- Travel score
- 5.9
- 2nd-best season
- Months
- Jun · Jul · Aug
Temperature in Seosan in Summer
Over the season highs climb from about 24°C in early June to 27°C by late August.
A typical summer day in Seosan reaches about 27°C and drops to 21°C overnight. The warmest of the three months is August, the coolest June.
How summer really feels in Seosan
Once humidity and wind are folded in, summer brings about 20 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.
Seosan 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 | 3° / -3° | 22 | 4.9 | 4 | 9.8 | 0.0 |
| Feb | 5° / -2° | 27 | 4.2 | 1.7 | 10.6 | 0.2 |
| Mar | 10° / 2° | 41 | 5.6 | 0.9 | 11.7 | 2.4 |
| Apr | 16° / 7° | 69 | 6.8 | 0 | 12.9 | 5.3 |
| May | 21° / 13° | 79 | 7 | 0 | 13.9 | 7.0 |
| Jun | 25° / 18° | 116 | 7.7 | 0 | 14.5 | 7.1 |
| Jul | 27° / 22° | 245 | 14.8 | 0 | 14.3 | 5.4 |
| Aug | 29° / 23° | 225 | 13.7 | 0 | 13.4 | 5.3 |
| Sep | 25° / 18° | 133 | 7.5 | 0 | 12.2 | 7.2 |
| Oct | 20° / 12° | 55 | 5.3 | 0 | 11 | 7.1 |
| Nov | 12° / 6° | 49 | 7.2 | 0.4 | 10 | 3.6 |
| Dec | 6° / -0° | 26 | 6.1 | 3.4 | 9.5 | 0.4 |
Cloud cover in Summer
The sky is clear or mostly clear about 28% of the time across summer.
Chance of precipitation in Summer
Seosan gets around 586 mm of rain over 36 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 11 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 h 18 min in early June to 12 h 54 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 5.0 kWh/m².
Hazard calendar for Seosan
In summer, Seosan overlaps its pacific typhoon and rainy season season. The full year is below, with each hazard's peak months called out.
Seosan sits in the Pacific typhoon belt; the season peaks July–October.
Seosan's rainy season runs June–September, when most of the year's rain falls.
Is summer a good time to visit Seosan?
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 Seosan for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Seosan in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Seosan sees daytime highs around 27°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 36 days see rain.
Sea temperature near Seosan in Summer
The nearest coast averages about 21°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 19 km away) is warmest in August at about 25°C and coldest in February near 5°C.
It's comfortable for a long swim from Jul 4 to Oct 7 — about 3.2 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 7 | 5 | 6 | 8 | 12 | 18 | 22 | 25 | 23 | 19 | 15 | 11 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Cool | Refreshing | Warm | Refreshing | Cool | Cool | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 7 | Bracing |
| Feb | 5 | Bracing |
| Mar | 6 | Bracing |
| Apr | 8 | Bracing |
| May | 12 | Bracing |
| Jun | 18 | Cool |
| Jul | 22 | Refreshing |
| Aug | 25 | Warm |
| Sep | 23 | Refreshing |
| Oct | 19 | Cool |
| Nov | 15 | Cool |
| Dec | 11 | Bracing |
UV index in Seosan 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 Seosan peaks around July 20 at about 7 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 23 at about 2 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 3 | 5 | 6 | 6 | 7 | 8 | 7 | 7 | 5 | 3 | 2 |
| Level | Low | Moderate | Moderate | High | High | High | Very high | Very high | Very high | High | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Low |
| Feb | 3 | Moderate |
| Mar | 5 | Moderate |
| Apr | 6 | High |
| May | 6 | High |
| Jun | 7 | High |
| Jul | 8 | Very high |
| Aug | 7 | Very high |
| Sep | 7 | Very high |
| Oct | 5 | High |
| Nov | 3 | Moderate |
| Dec | 2 | Low |
Air quality in Seosan 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 Seosan is worst in March — around 92 µg/m³ PM2.5 (unhealthy), about 2.0× the cleanest month (July, 46 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) | 83 | 85 | 92 | 75 | 62 | 57 | 46 | 47 | 61 | 74 | 79 | 73 |
| Level | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Poor | Poor | Unhealthy | Unhealthy | Unhealthy | Unhealthy |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 83 | Unhealthy |
| Feb | 85 | Unhealthy |
| Mar | 92 | Unhealthy |
| Apr | 75 | Unhealthy |
| May | 62 | Unhealthy |
| Jun | 57 | Unhealthy |
| Jul | 46 | Poor |
| Aug | 47 | Poor |
| Sep | 61 | Unhealthy |
| Oct | 74 | Unhealthy |
| Nov | 79 | Unhealthy |
| Dec | 73 | Unhealthy |
Where is Seosan?
Seosan sits at 36.8°N, 126.5°E, 33 m above sea level, in South Korea. The nearest listed city is Tangjin, 20 km away.
Topography around Seosan
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Seosan.
Within 3 km, the terrain around Seosan has only modest variations in elevation — a maximum elevation change of 192 m around an average of 43 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 643 m; within 80 km, large variations in elevation — a maximum elevation change of 769 m.
The land around Seosan is covered by cropland (33%), trees (30%) and artificial surfaces (30%) within 3 km, cropland (39%) and trees (38%) within 16 km, and water (53%) and trees (25%) 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 Seosan (36.7817°, 126.4522°, elevation 33 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.