Busan weather by month
Busan runs from about 2°C in January to 28°C in August, with October the wettest month at 259 mm.
warmest month
August
28°C
coolest month
January
2°C
wettest month
October
259 mm
worst air month
March
31 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 2°C | 54 mm | 231 h | 18 |
| February | 6°C | 119 mm | 155 h | 22 |
| March | 7°C | 122 mm | 256 h | 31 |
| April | 14°C | 130 mm | 223 h | 21 |
| May | 17°C | 114 mm | 328 h | 17 |
| June | 22°C | 237 mm | 254 h | 14 |
| July | 26°C | 224 mm | 252 h | 13 |
| August | 28°C | 132 mm | 368 h | 16 |
| September | 25°C | 243 mm | 291 h | 12 |
| October | 18°C | 259 mm | 218 h | 12 |
| November | 11°C | 102 mm | 242 h | 20 |
| December | 2°C | 0 mm | 271 h | 18 |
About 3,089 hours of sun a year. Roughly 172 rainy days a year.
These are long-run climate normals, not a forecast. A given year can sit well outside them. PM2.5 is a global model: near the coast it counts sea salt as fine particulate and reads high against ground stations, sometimes by a factor of two. Use the shape of the year, not the absolute number.
where these numbers come from
- · Temperature, rainfall and sunshine: ECMWF ERA5 reanalysis climate normals via Open-Meteo (CC BY 4.0), fetched once and stored.
- · PM2.5: Copernicus CAMS reanalysis, monthly means. Modelled, not station readings; near coasts CAMS counts sea salt as PM2.5 and reads high.
Last reviewed 2026-05-23. Full method, licences and the list of sources we rejected are on the methodology page.