Busan records about 1519mm of rain across roughly 99 wet days a year, which is a 27% chance on an average day. July is the wettest month at 291mm (19% of the annual total) and December the driest at 26mm. Local rain type: monsoon. Busan gets intense monsoon rain in summer — July's downpours can be extreme. The beach city transforms between dry spring and monsoon summer.
Chance of rain on an average day: 27%
Rainfall climatology for Busan. 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 | 1519mm |
| Rain days per year | 99 |
| Odds on an average day | 27% |
| Wettest month | July — 291mm over 21 days |
| Driest month | December — 26mm over 2 days |
| Rain type | monsoon |
| Best dry window | September through November offers warm, dry conditions — the best season for beach activities. |
| Worst rain window | July and August bring the heaviest monsoon rain with occasional typhoon threats. |
July delivers 1019% more rain than December (291mm vs 26mm). That gap is the difference between planning around showers and ignoring them.
No single month holds more than 19% of the annual total, so rain in Busan is spread through the year — there is no season you can rely on being dry.
Busan rain arrives in short, heavy bursts — shelter and timing matter more than gear.
Rain falls on about 21 days in July against 2 in December — 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 | 36mm | 3 | 10% | 7°C |
| February | 42mm | 3 | 10% | 7°C |
| March | 76mm | 6 | 20% | 10°C |
| April | 98mm | 7 | 23% | 15°C |
| May | 100mm | 7 | 23% | 21°C |
| June | 198mm | 14 | 47% | 26°C |
| July | 291mm | 21 | 70% | 29°C |
| August | 232mm | 17 | 57% | 29°C |
| September | 164mm | 12 | 40% | 26°C |
| October | 46mm | 3 | 10% | 21°C |
| November | 52mm | 4 | 13% | 15°C |
| December | 26mm | 2 | 7% | 10°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Busan 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.
Busan records rain on roughly 99 days a year — about a 27% chance on any given day — totalling around 1519mm.
July, with about 291mm over 21 rain days. That is 19% of the entire year's rainfall in a single month.
December is the driest month at 26mm across roughly 2 days. September through November offers warm, dry conditions — the best season for beach activities.
Busan gets intense monsoon rain in summer — July's downpours can be extreme. The beach city transforms between dry spring and monsoon summer.
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.