Seongnam-si in Summer
In summer (June, July and August), Seongnam-si sees average daytime highs around 28°C and overnight lows near 20°C, with 752 mm of rain over about 42 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 22% of the time across summer, and the air most often feels oppressive.
Summer is Seongnam-si's 2nd-best season to visit on our travel score. For the whole year in context, see Seongnam-si's year-round climate.
- Avg daytime high
- 28°C
- warmest season of the year
- Avg overnight low
- 20°C
- Rainfall
- 752 mm
- 42 wet days
- Avg wind
- 8 km/h
- Travel score
- 5.4
- 2nd-best season
- Months
- Jun · Jul · Aug
Temperature in Seongnam-si 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 Seongnam-si reaches about 28°C and drops to 20°C overnight. The warmest of the three months is August, the coolest June.
How summer really feels in Seongnam-si
Once humidity and wind are folded in, summer brings about 22 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.
Seongnam-si 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 | 2° / -7° | 21 | 3.8 | 2.6 | 9.7 | 0.0 |
| Feb | 5° / -5° | 28 | 4.2 | 2 | 10.6 | 0.3 |
| Mar | 11° / -0° | 43 | 6.4 | 1.6 | 11.7 | 2.8 |
| Apr | 17° / 6° | 79 | 7.3 | 0.1 | 12.9 | 5.9 |
| May | 23° / 12° | 104 | 8.5 | 0 | 14 | 7.1 |
| Jun | 26° / 17° | 135 | 9.3 | 0 | 14.5 | 6.5 |
| Jul | 28° / 21° | 340 | 17.2 | 0 | 14.3 | 4.8 |
| Aug | 29° / 22° | 277 | 15.7 | 0 | 13.4 | 4.8 |
| Sep | 25° / 16° | 134 | 8.4 | 0 | 12.3 | 6.9 |
| Oct | 19° / 9° | 58 | 5.5 | 0 | 11 | 7.0 |
| Nov | 11° / 2° | 50 | 7.3 | 0.7 | 10 | 3.1 |
| Dec | 4° / -5° | 25 | 4.7 | 2.1 | 9.5 | 0.1 |
Cloud cover in Summer
The sky is clear or mostly clear about 22% of the time across summer.
Chance of precipitation in Summer
Seongnam-si gets around 752 mm of rain over 42 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 8 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 h 24 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 4.7 kWh/m².
Hazard calendar for Seongnam-si
In summer, Seongnam-si overlaps its pacific typhoon and rainy season season. The full year is below, with each hazard's peak months called out.
Seongnam-si sits in the Pacific typhoon belt; the season peaks July–October.
Seongnam-si's rainy season runs July–August, when most of the year's rain falls.
Is summer a good time to visit Seongnam-si?
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 Seongnam-si for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Seongnam-si in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Seongnam-si sees daytime highs around 28°C and nights near 20°C. Pack light clothes and rain gear. Worth having: sun protection. About 42 days see rain.
Sea temperature near Seongnam-si in Summer
The nearest coast averages about 20°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 46 km away) is warmest in August at about 24°C and coldest in February near 4°C.
It's comfortable for a long swim from Jul 11 to Oct 13 — about 3.1 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 6 | 4 | 5 | 8 | 12 | 17 | 21 | 24 | 23 | 20 | 15 | 10 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Cool | Refreshing | Refreshing | Refreshing | Cool | Bracing | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 6 | Bracing |
| Feb | 4 | Bracing |
| Mar | 5 | Bracing |
| Apr | 8 | Bracing |
| May | 12 | Bracing |
| Jun | 17 | Cool |
| Jul | 21 | Refreshing |
| Aug | 24 | Refreshing |
| Sep | 23 | Refreshing |
| Oct | 20 | Cool |
| Nov | 15 | Bracing |
| Dec | 10 | Bracing |
UV index in Seongnam-si in Summer
Clear-sky midday UV across summer averages around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Seongnam-si peaks around August 11 at about 8 (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 8 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 3 | 4 | 6 | 6 | 7 | 8 | 8 | 7 | 5 | 3 | 2 |
| Level | Low | Moderate | Moderate | High | High | High | Very high | Very high | Very high | Moderate | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Low |
| Feb | 3 | Moderate |
| Mar | 4 | Moderate |
| Apr | 6 | High |
| May | 6 | High |
| Jun | 7 | High |
| Jul | 8 | Very high |
| Aug | 8 | Very high |
| Sep | 7 | Very high |
| Oct | 5 | Moderate |
| Nov | 3 | Moderate |
| Dec | 2 | Low |
Air quality in Seongnam-si 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 Seongnam-si is worst in March — around 123 µg/m³ PM2.5 (unhealthy), and holds fairly steady the rest of the year.
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 106 | 108 | 123 | 104 | 96 | 91 | 79 | 78 | 97 | 115 | 118 | 100 |
| Level | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 106 | Unhealthy |
| Feb | 108 | Unhealthy |
| Mar | 123 | Unhealthy |
| Apr | 104 | Unhealthy |
| May | 96 | Unhealthy |
| Jun | 91 | Unhealthy |
| Jul | 79 | Unhealthy |
| Aug | 78 | Unhealthy |
| Sep | 97 | Unhealthy |
| Oct | 115 | Unhealthy |
| Nov | 118 | Unhealthy |
| Dec | 100 | Unhealthy |
Where is Seongnam-si?
Seongnam-si sits at 37.4°N, 127.1°E, 80 m above sea level, in South Korea. The nearest listed city is Gwangju, 11 km away.
Topography around Seongnam-si
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Seongnam-si.
Within 3 km, the terrain around Seongnam-si has only modest variations in elevation — a maximum elevation change of 205 m around an average of 64 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 645 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,443 m.
The land around Seongnam-si is covered by artificial surfaces (58%) and trees (34%) within 3 km, trees (58%) and artificial surfaces (33%) within 16 km, and trees (53%) 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 Seongnam-si (37.4386°, 127.1378°, elevation 80 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.