Phong Nha weather by month
Phong Nha runs from about 20°C in December to 31°C in August, with October the wettest month at 658 mm.
warmest month
August
31°C
coolest month
December
20°C
wettest month
October
658 mm
worst air month
April
31 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 20°C | 116 mm | 192 h | 19 |
| February | 23°C | 87 mm | 177 h | 15 |
| March | 24°C | 63 mm | 200 h | 19 |
| April | 31°C | 13 mm | 332 h | 31 |
| May | 29°C | 234 mm | 280 h | 13 |
| June | 31°C | 63 mm | 293 h | 9 |
| July | 29°C | 177 mm | 273 h | 6 |
| August | 31°C | 56 mm | 326 h | 9 |
| September | 28°C | 482 mm | 210 h | 8 |
| October | 25°C | 658 mm | 205 h | 11 |
| November | 23°C | 400 mm | 147 h | 15 |
| December | 20°C | 232 mm | 88 h | 17 |
About 2,723 hours of sun a year. Roughly 194 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 2026-05-25. Full method, licences and the list of sources we rejected are on the methodology page.