Lang Son Weather, Best Time for Holidays

Lang Son Province has a tropical monsoon climate like most of northern Vietnam but does not often have too high temperatures even in the summer. The temperatures in Lang Son are often at least 2-3oC lower than neighboring regions all year round.

Except for temperatures in hill stations and high-altitude regions in Vietnam, Lang Son Province has the lowest averaged temperatures thanks to its location which makes it among the first lands in Vietnam to receive both the winter monsoon and summer monsoon.

Bac Son Valley, Lang Son Province
Bac Son Valley, Lang Son Province

There are two main monsoons affecting Lang Son: the Southeasterly Monsoon in the summer from May through September and the Northeasterly Monsoon in the winter from October through April. The former wind is humid while the latter one is cold and dry. As Lang Son is in the Northeast of Vietnam that the province is strongly influenced by these winds.

The temperatures in Lang Son in the summer are often between 26-32oC and in the winter between 10-20oC. During coldest months from November through February, the temperatures may get down to freezing point and there may be snow or frost in high mountains in Lang Son. The hottest months are June, July during which time the temperatures may reach 35oC. It may but not often get above 36oC in Lang Son.

During the summer months, especially from June through September, Lang Son may be affected by tropical depressions or storms which may cause torrential rains and flash floods. It does not receive much rainfall in the winter but there are light drizzles at the beginning and the end of the winter which often make the air damp. The annual rainfall in Lang Son is between 1,200-1,600mm.

A breathtaking view from the top of the Na Lay Mountain at Bac Son
A breathtaking view from the top of the Na Lay Mountain at Bac Son

Lang Son weather and temperatures by month
- January: some sun, clouds Relatively dry, some possible light rain when hit by a new spell of cold wind, 9-26oC.
- February: some sun, cold and relatively dry, possible light rain when hit by a new spell of cold wind, 11-21oC mostly.
- March: sun, clouds, mostly cold and dry, mixed cloudy and sunny days, some possible light drizzles, 12-28oC mostly.
- April: sun, clouds, some days with damp air and fog, 16-30oC.
- May: Sun mostly, showers and thunderstorms, possible but not often heat strikes, 17-33oC.
- June: Sun mostly, rain and thunderstorms often, possible landslides and flash floods, possible heat strikes, 22-35oC.
- July: Sun mostly, more torrential rains, possible storms, landslides and flash floods, 24-34oC mostly.
- August: Sun, clouds, some possible storms, torrential rain, 24-32oC.
- September: Sun, clouds, some possible storms, torrential rain, 22-32oC.
- October: Sun, clouds, some fabulous days, some torrential rain, 11-31oC.
- November: Sun, clouds, some fabulous days, some isolated rain, 11-28oC.
- December: Sun, clouds, some fabulous days, some isolated light rain, 0-25oC.

The best time for nice weather to visit Lang Son
The best time to visit Lang Son is during the dry season and when the temperatures are pleasant. These weather conditions are mostly found in October and the first half of November, or March and April.

If you do not like the cold, then avoid visiting Lang Son during the last 20 days of December and during the first 20 days of January. Those of you who are planning a trekking adventure tour in Lang Son, then you’ll definitely want to visit the land during the cold and dry winter. For those on bike tours in Lang Son, you had better do it during the dry and pleasant temperature times.

Those who plan for a photography tour to the Bac Son Valley, you may want to do it in late May or September when the rice fields have mesmerizing colors.