The climate in Bach Ma National Park is tropical with two distinctive seasons caused by the monsoon winds. There is hot and dry wind occurring from May to August and can be typhoon from June to November.
Bach Ma mountain is the wettest place within Vietnam with approximately 8,000 mm rainfall each year, mainly falling in the period between September and December. Areas at the foot of the mountain still receive about 3,000 mm annual precipitation. Air humidity is mainly between 85 % and 95 %. March and April are the driest months but even during that time humidity is rarely lower than 75 %.
Because of its high altitude, the summit area of Bach Ma mountain is always around 7 degrees cooler than the surrounding lowland areas. Temperatures in December and January can be quite cool with around 15 degree centigrade. The hottest months of the year are from May to August.
The weather conditions in the park area can change very quickly, in the morning being sunny changing to cloudy with heavy rain in the afternoon. Because of the proximity of the sea there are often strong winds.
The time in February is famous for the red Rhododendron simsii blossoms, well worth discovering and exploring with dry weather and still favorable temperatures. Most people visit Bach Ma in summer to escape the heat, and the park is particularly busy during weekends in June, July and August. The first torrential rainfalls in September mark the end of the high tourist season and bring back silence and serenity to the area.