Winter needs insulated layers; late spring and autumn are milder; July and August bring heat, humidity and rain risk.
January to March
January and February are the coldest part of the year, with dry air and possible snow or ice. March is transitional: afternoons may improve while mornings and evenings remain cold.
April to June
April and May usually become milder and greener. June begins to feel warmer and more humid, so packing should shift from insulating layers toward breathable clothing and rain protection.
July to September
July and August bring the strongest heat, humidity and summer-rain risk. September often starts warm and gradually becomes more comfortable, but storms can still affect plans.
October to December
October is commonly suited to outdoor walking, while November cools quickly. December requires winter layers, especially for riverside routes and evening viewpoints.
Check the actual travel week
Monthly patterns are context, not a forecast. Compare the Seoul observation time, precipitation and wind shortly before each outdoor day.
Before you act
- Pack for the coldest part of the day, not only the average high.
- Carry compact rain protection in summer.
- Review the Seoul forecast again after arrival.
Related planning pages
Seoul weather · Seoul travel guide · What to Wear in Seoul by Season · All travel guides
Seoul Weather by Month FAQ
Can monthly averages predict rain on my trip?
No. They describe a broad pattern; use a short-range forecast for your dates.
Why can the same temperature feel different?
Wind, humidity, sun exposure and time spent outdoors can change how conditions feel.