Hakone weather by month
Hakone runs from about 7°C in January to 28°C in August, with June the wettest month at 342 mm.
warmest month
August
28°C
coolest month
January
7°C
wettest month
June
342 mm
worst air month
February
18 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 7°C | 55 mm | 242 h | 15 |
| February | 8°C | 176 mm | 176 h | 18 |
| March | 9°C | 264 mm | 235 h | 16 |
| April | 16°C | 177 mm | 227 h | 15 |
| May | 18°C | 280 mm | 252 h | 14 |
| June | 22°C | 342 mm | 250 h | 12 |
| July | 27°C | 96 mm | 308 h | 10 |
| August | 28°C | 239 mm | 318 h | 14 |
| September | 26°C | 74 mm | 276 h | 12 |
| October | 20°C | 196 mm | 214 h | 13 |
| November | 14°C | 190 mm | 199 h | 16 |
| December | 8°C | 5 mm | 265 h | 14 |
About 2,962 hours of sun a year. Roughly 207 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 2026-05-24. Full method, licences and the list of sources we rejected are on the methodology page.