Seoul records about 1394mm of rain across roughly 108 wet days a year, which is a 30% chance on an average day. July is the wettest month at 395mm (28% of the annual total) and January the driest at 21mm. Local rain type: monsoon. Critical from June through September during the jangma (monsoon) season. Winter is dry and cold. Korean convenience stores sell quality umbrellas at every corner.
Chance of rain on an average day: 30%
Rainfall climatology for Seoul. The live hour-by-hour answer for today loads at the top of this page from Open-Meteo and refreshes through the day — the figures below describe a typical year, not today.
Last updated: · Live forecast data refreshes hourly.
| Annual rainfall | 1394mm |
| Rain days per year | 108 |
| Odds on an average day | 30% |
| Wettest month | July — 395mm over 30 days |
| Driest month | January — 21mm over 2 days |
| Rain type | monsoon |
| Best dry window | October offers spectacular autumn foliage with crisp, dry weather — the best month to visit. |
| Worst rain window | July brings monsoon-level rainfall — nearly 400mm in a single month. |
July delivers 1781% more rain than January (395mm vs 21mm). That gap is the difference between planning around showers and ignoring them.
28% of the year's rain falls in July alone, so Seoul has a genuine wet season rather than evenly spread showers.
Seoul rain arrives in short, heavy bursts — shelter and timing matter more than gear.
Rain falls on about 30 days in July against 2 in January — the frequency swing matters more for planning than the millimetre totals.
Climate normals. Use them to judge whether today's live forecast at the top of the page is typical or unusual for the season.
| Month | Rainfall | Rain days | Chance on a given day | Highs |
|---|---|---|---|---|
| January | 21mm | 2 | 7% | 2°C |
| February | 25mm | 2 | 7% | 2°C |
| March | 46mm | 3 | 10% | 6°C |
| April | 64mm | 5 | 17% | 12°C |
| May | 105mm | 8 | 27% | 20°C |
| June | 133mm | 10 | 33% | 26°C |
| July | 395mm | 30 | 100% | 30°C |
| August | 348mm | 26 | 87% | 30°C |
| September | 169mm | 13 | 43% | 26°C |
| October | 52mm | 4 | 13% | 20°C |
| November | 53mm | 4 | 13% | 12°C |
| December | 21mm | 2 | 7% | 6°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Seoul we combine the hourly probability curve, expected volume in millimetres, and the city's own rainfall record into a single umbrella verdict.
| Factor | Weight | What it measures |
|---|---|---|
| Hourly probability | 40% | Peak and sustained chance of measurable rain across the next 24 hours. |
| Expected volume | 30% | Total millimetres, which separates a passing shower from a genuine soaking. |
| Timing & duration | 20% | When rain starts, when it eases, and the longest continuous dry window. |
| Local rain type | 10% | Drizzle, brief showers, thunderstorms or monsoon — each needs different gear. |
Live hourly values come from Open-Meteo and refresh through the day. Monthly rainfall figures are climate normals, so they describe a typical year rather than a forecast.
Seoul records rain on roughly 108 days a year — about a 30% chance on any given day — totalling around 1394mm.
July, with about 395mm over 30 rain days. That is 28% of the entire year's rainfall in a single month.
January is the driest month at 21mm across roughly 2 days. October offers spectacular autumn foliage with crisp, dry weather — the best month to visit.
Critical from June through September during the jangma (monsoon) season. Winter is dry and cold. Korean convenience stores sell quality umbrellas at every corner.
No. Probability is the chance that at least 0.2mm of rain falls at your location at some point in the period. Check the expected millimetres alongside it: 40% with 0.4mm is a passing shower, 40% with 12mm is a soaking.