The weather conditions of Phong Nha – Ke Bang
The annual mean temperature is 23 – 25 degree celsius. The highest temperature is in June, July and August, with mean temperature greater than 28 degree celsius. Daily variation in temperature is high, about 10 degree celsius in summer and 8 degree celsius in winter.
Phong Nha – Ke Bang is situated in region of the high rainfall with an average of 2,000 mm to 2,500 mm per year. The highest rainfall is concentrated in September, October and November. The rainy season is from July to December . The dry season is from January to June and the lowest rainfall is in February and March.
Mean annual relative humidity is 83 – 84%. In the period September to April, humidity is highest (85-90%). The period of May to August experiences hot and dry northwesterly winds, so that humidity is lower.
The northeasterly winds and sometimes the easterly or southeasterly winds appeared in the winter . In the summer a southwesterly wind is common, which sometimes changes to a hot and dry northwesterly wind, in June, July, and August. The period from September to April, the easterly and southeasterly winds sometimes come from the sea.
The flooding season takes place from September to November, with the largest floods appearing in the middle of September and October. Besides the main rainy and flooding season, rains in May and June sometime cause large floods. In the dry season, from February to August, almost all the streams in Phong Nha – Ke Bang become “ dead streams”. The water level in the Chay and Son Rivers is very low at this time.
The best time to go to Phong Nha – Ke Bang
Similar to Northern Vietnam’s weather, Phong Nha – Ke Bang National Park has a typical tropical monsoon weather with hot temperature in summer and high humidity. In summer it can go up to 41°C and it also can drop as low as 6°C in winter. As such, it is not advisable to go there during typhoon and rainy season, especially from October to December, although the temperature inside the cave is still cool (around 20°C) but the temperature outside is simply unbearable. You may not be easy and comfortable with rain or bad weather or typhoon during the month of October to December as the weather can turn cold.
So, we recommend to visit or join adventure tour in Phong Nha – Ke Bang National Park from February to August, the weather is more ideal