Best Time to Visit Seoul (2026): Weather, Festivals and Crowds Month by Month

Seoul's spring, roughly late March through May, opens with the city's most photographed week: cherry blossoms along the Yeouido riverside and Seokchon Lake, usually peaking for a short window somewhere between late March and early April depending on how the winter ran. Temperatures climb steadily through the season into comfortable daytime highs in the high teens to low 20s°C, making it one of the two best stretches for walking Bukchon's hanok alleys, Gyeongbokgung's palace grounds, or Namsan's hiking trails without fighting heat or heavy rain.

Autumn, September through November, mirrors spring's appeal from the other direction — the heat and humidity of summer break, and the foliage season (usually peaking in late October to early November around Seoul, later than Japan's but following a similar pattern) turns Namsan and the palace grounds a genuine orange-and-red spectacle. Both shoulder seasons draw the heaviest domestic and international tourist volume of the year, so popular palace time slots and well-reviewed guided tours are worth booking a few days ahead rather than assuming same-day availability.

June through August in Seoul brings genuinely hot, humid weather with daytime highs regularly in the low 30s°C, but the detail that catches first-time visitors off guard is the jangma, Korea's monsoon rain season, which typically runs through most of July and can dump heavy, sustained rainfall for days at a stretch. It isn't a single storm system the way a typhoon is — it's a persistent wet pattern that can derail an outdoor-heavy itinerary, particularly a DMZ day trip or a Han River picnic, if you don't build in flexible days.

The upside: indoor attractions, the city's dense museum and palace-adjacent cafe culture, and night markets under covered stalls are largely unaffected, and accommodation can be slightly cheaper outside the peak cherry-blossom and foliage windows.

December through February runs cold by most visitors' standards, with daytime highs often sitting below freezing and occasional cold fronts pushing temperatures lower still, but the air is dry and the skies are frequently clear rather than grey, which actually suits a Gyeongbokgung or N Seoul Tower visit better than summer's haze. It's also the quietest and cheapest season for flights and hotels, and it's when Seoul's hot drink and heated-floor cafe culture, and winter illumination displays around Myeongdong and the palaces, come into their own.

Pack for genuine cold — a proper coat, not just layers — and know that outdoor hanbok photoshoots at Gyeongbokgung, while still popular, are a colder experience than the same rental in April or October.