Quick answer: Spring and autumn are often comfortable choices for a first sightseeing trip, but choose dates around your priorities and check the forecast. A seasonal guide is not a prediction of conditions on your travel day.
Spring: flowers and changing temperatures
March to May brings a transition from cold weather to warmer days. Cherry-blossom timing differs by region and year; a broad late-March-to-April window is useful for early planning, not a guarantee of peak bloom. Late April or May can be pleasant even when the best-known cherry blossoms have finished.
Pack layers and check air-quality information as well as temperature. For a flower-focused trip, keep some flexibility between destinations rather than assuming every city blooms on the same weekend.
Summer: rain, heat and indoor alternatives
June to August can be hot and humid. The rainy season is not confined to July, and heavy rain or typhoons can disrupt outdoor plans beyond the usual seasonal window. Check Korea Meteorological Administration forecasts and warnings close to travel.
Plan indoor alternatives for hiking, beaches and outdoor festivals. A beach holiday still requires weather and local access checks; do not treat the south coast as exempt from summer rain or storms.
Autumn: walking and foliage
September to November can be a good period for neighbourhood walks and mountain scenery. Foliage progresses differently by latitude, elevation and year; use a current regional forecast if colour is the reason for your trip.
Bring a layer for evenings and mountain conditions. Bukhansan spans Seoul and neighbouring Gyeonggi areas rather than lying entirely inside Seoul. Check the particular trailhead, access restrictions and return transport.
Winter: cities and snow trips
December to February can be cold, especially inland and in the mountains. A snowy ski resort and a snow-free city street can exist on the same day. Confirm resort opening, lift operation and equipment arrangements rather than assuming a fixed December opening date.
Allow more travel flexibility around snow and ice. Coastal Jeju can feel different from Hallasan's upper slopes; lowland weather is not a reliable guide to summit conditions.
Prices and crowds
Winter or shoulder-season dates may offer value, but no month guarantees the lowest airfare or hotel price. School holidays, Lunar New Year, Chuseok, festivals and concerts can change the picture. Compare actual quotes and cancellation conditions.
For a first visit, choose a manageable itinerary and leave space for weather changes. Match the season to your main activity, then confirm the event calendar, attraction opening notices and entry requirements for your dates.