Discover the best time of year, based on historical climate, temperature, and precipitation.
The best weather in Seongnam-si is from May, June, October. — consistent weather climate
🌦Humid
| Score | 25 | 26 | 42 | 74 | 81 | 76 | 42 | 46 | 73 | 84 | 38 | 24 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Climate | Polar | Cold | Cold | Mild | Mild | Humid | Rainy | Rainy | Humid | Mild | Cold | Polar |
| Temperature | -7–2°C | -5–5°C | 0–12°C | 6–18°C | 11–23°C | 17–27°C | 22–29°C | 22–29°C | 17–25°C | 9–18°C | 2–11°C | -5–3°C |
| Feels like | -11–-3°C | -9–1°C | -4–8°C | 4–16°C | 10–22°C | 18–29°C | 25–33°C | 26–34°C | 18–27°C | 7–17°C | -1–8°C | -9–-1°C |
| Precipitation | 19mm 3 days | 28mm 4 days | 39mm 5 days | 66mm 6 days | 97mm 7 days | 120mm 10 days | 312mm 20 days | 257mm 18 days | 139mm 10 days | 69mm 5 days | 66mm 6 days | 28mm 4 days |
| Sunshine | 7.7h ☀︎ 77% | 8.3h ☀︎ 77% | 9.0h ☀︎ 76% | 9.3h ☀︎ 70% | 9.8h ☀︎ 69% | 9.6h ☀︎ 65% | 6.7h ☀︎ 46% | 8.5h ☀︎ 63% | 8.3h ☀︎ 67% | 8.2h ☀︎ 73% | 7.2h ☀︎ 71% | 7.1h ☀︎ 74% |
| Wind | W · 14 km/h | W · 16 km/h | W · 16 km/h | SW · 17 km/h | SW · 16 km/h | SW · 14 km/h | S · 14 km/h | SW · 13 km/h | NE · 12 km/h | NW · 13 km/h | NW · 13 km/h | W · 14 km/h |
| Humidity (%) | 59% | 61% | 65% | 64% | 67% | 71% | 82% | 82% | 77% | 73% | 71% | 63% |
| Day length | 9.9h | 10.8h | 12.0h | 13.2h | 14.2h | 14.7h | 14.5h | 13.6h | 12.4h | 11.2h | 10.2h | 9.6h |
December brings Seongnam its heaviest crowds of the year despite delivering its most punishing freeze, while October offers immaculate, golden-lit days alongside some of the thinnest foot traffic on the calendar.
Spilling immediately south from the Seoul border, Seongnam is modern Korea laid out by design: a city engineered from the ground up, where the older working-class hills of Sujeong District and Jungwon District give way to the manicured avenues, sunken garden paths, and glass tech headquarters of Bundang District. Most travelers never think of Seongnam as an independent destination, treating it as an overflow commuter suburb of the capital or a business stop. But when experienced on the ground, its wide river greenways and landscaped urban parks offer a distinctly calmer, roomier slice of metropolitan life than the core across the boundary. The catch is entirely chronological. Visitors pack its transit nodes and shopping districts to the brim during the bitter dead of winter, completely overlooking the glorious, sunlit months of late spring and autumn when the city's meticulous outdoor planning actually pays off.
December is Seongnam at its most baffling: the busiest month on the city's calendar pairs directly with its worst weather. Commuters, holiday shoppers, and end-of-year gatherings flood the subway corridors and subterranean concourses, even as the wind knifes between the high-rises and apparent temperatures sink well below freezing. The planned efficiency of the city means you can scurry from train platform to heated mall without touching cold air, which explains how so many people endure it, but walking outdoors is an endurance trial.
January and February ease slightly in crowd pressure, but the cold digs in its heels. The landscaped waters of Tancheon, the broad stream slicing through Bundang District, turn glassy with ice, and the wide pedestrian boulevards become wind tunnels. There is an austere, steel-and-granite beauty to the city under pale winter sunlight, especially when snow dusts the low ridges buffering the valley. Yet spending more than half an hour outside requires heavy down coats and thermal boots, and street life retreats entirely into basement arcades and steamy soup shops.
March hints at transition, but the chill lingers stubbornly; early spring afternoons feel deceptively sharp, and the trees lining the grid remain bare. April brings the real relief. As the city warms, the plum and cherry blossoms along Tancheon burst into color, drawing neighborhood walkers out onto the paved river trails. The air sits at a comfortable, brisk mid-spring temperature, making it the first month where wandering aimlessly through the residential quarters actually feels pleasant.
Then comes May, which represents one of the greatest discrepancies in the region's travel habits. May delivers the second-best weather of the entire year—clear, soft sunshine, pleasantly warm afternoons around 23 degrees, and lush green canopies—yet crowd levels stay remarkably modest. Families spread picnic mats across the lawns of Bundang Central Park, and the lakeside trails at Yuldong Park fill with local strollers rather than tour groups. It is an effortless, airy window where the urban design works exactly as intended, giving you breathing room that central Seoul rarely provides.
June kicks off with rising humidity and a surge in domestic visitors, but conditions remain manageable for outdoor dining and evening walks before the heavy rains hit. By July, however, the summer monsoon arrives in earnest, and the city undergoes a drastic climate shift. Rain does not fall in gentle, poetic drizzles here; it dumps in intense, drenching downpours that turn walking paths into torrents and keep you pinned under covered awnings.
July and August combine oppressive moisture with apparent temperatures soaring into the mid-thirties. The air feels soupy and thick from dawn to midnight. Tancheon swells dangerously high after torrential cloudbursts, cutting off riverside bike routes, while the humidity turns even a brief stroll through Sujeong District into a sweat-soaked trek. If you find yourself in Seongnam during midsummer, follow the locals: retreat into the air-conditioned labyrinth of department stores, indoor sports complexes, and basement transit networks until sundown.
September marks the end of the deluge. While occasional late-summer showers pass through, the humidity breaks decisively mid-month, ushering in clear skies and crisp evening breezes. It sets the stage for October, which is indisputably the finest month to be in Seongnam. The weather score reaches its absolute zenith, while visitor numbers drop to their lowest annual levels, creating an ideal combination of comfort and solitude.
In October, the deciduous trees across Bundang Central Park and around the lake at Yuldong Park turn brilliant shades of crimson, russet, and yellow. Daytime temperatures hover in the upper teens, creating crisp, invigorating air under brilliant blue skies. The wide sidewalks and pedestrian bridges, designed decades ago to balance urban density with parkland, suddenly make absolute sense. You can walk for miles across the districts without sweating, shivering, or jostling through crowds.
November brings the curtain down quickly. The golden leaves drop, the dry continental winds return from the north, and by mid-month the daytime warmth dissolves. Crowd levels begin their climb back toward the holiday peak, even as outdoor comfort evaporates, closing out the brief window when Seongnam is at its most welcoming.