Seoul Climate by Month – Rainy Season, Temperature Averages

Summary

The climate figures for Seoul are averaged from 2016–2025 observations (10 years). Annual rainfall averages about 1,300 mm.

The rainy season runs May–September. The wettest month is July with 313.4 mm across 17 rain days; the driest is January at just 18 mm.

The hottest month is August (average high 29.4°C) and the coolest is January (1.9°C).

The most comfortable time to visit Seoul is January — less rain and milder heat.

Monthly averages · 2016–2025

Monthly averagesHighLowRainfallRainy season
January1.9°-6.6°18 mm
3
February4.7°-5.0°25 mm
5
March11.6°0.3°43 mm
6
April17.7°6.4°64 mm
7
May22.6°11.8°111 mm
8
June27.0°17.7°126 mm
10
July29.2°22.3°313 mm
17
August29.4°22.7°276 mm
16
September25.3°17.4°160 mm
9
October18.6°9.4°85 mm
7
November11.2°1.7°51 mm
6
December3.0°-5.3°28 mm
5

Monthly averages

Seoul