Lạng Sơn in Fall
In fall (September, October and November), Lạng Sơn sees average daytime highs around 27°C and overnight lows near 20°C, with 290 mm of rain over about 37 wet days across the season. It is the 2nd-warmest season and the 3rd-wettest season.
Over the season highs ease from about 30°C in early September to 21°C by late November. The sky is clear or mostly clear about 28% of the time across fall, and the air most often feels oppressive.
Fall is Lạng Sơn's best season of the year to visit on our travel score. For the whole year in context, see Lạng Sơn's year-round climate.
- Avg daytime high
- 27°C
- 2nd-warmest season
- Avg overnight low
- 20°C
- Rainfall
- 290 mm
- 37 wet days
- Avg wind
- 9 km/h
- Travel score
- 5.9
- best season of the year
- Months
- Sep · Oct · Nov
Temperature in Lạng Sơn in Fall
Over the season highs ease from about 30°C in early September to 21°C by late November.
A typical fall day in Lạng Sơn reaches about 27°C and drops to 20°C overnight. The warmest of the three months is September, the coolest November.
How fall really feels in Lạng Sơn
Once humidity and wind are folded in, fall brings about 20 days that feel above 32°C and 0 that feel at or below 0°C.
The story in fall is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Lạng Sơn weather by month
How the three fall months (September, October and November) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 17° / 11° | 57 | 11.1 | 10.8 | 5.1 |
| Feb | 19° / 13° | 44 | 10.1 | 11.2 | 5.6 |
| Mar | 21° / 16° | 79 | 14.4 | 11.8 | 5.5 |
| Apr | 26° / 20° | 97 | 14.9 | 12.5 | 5.5 |
| May | 29° / 23° | 221 | 21.2 | 13 | 4.0 |
| Jun | 30° / 25° | 257 | 23.6 | 13.3 | 3.0 |
| Jul | 31° / 25° | 270 | 24.9 | 13.2 | 2.9 |
| Aug | 30° / 24° | 285 | 25.3 | 12.7 | 3.0 |
| Sep | 29° / 23° | 164 | 18.3 | 12.1 | 4.2 |
| Oct | 27° / 20° | 75 | 10.9 | 11.5 | 6.4 |
| Nov | 23° / 16° | 50 | 7.9 | 11 | 7.1 |
| Dec | 19° / 12° | 45 | 8.2 | 10.7 | 6.3 |
Cloud cover in Fall
The sky is clear or mostly clear about 28% of the time across fall.
Chance of precipitation in Fall
Lạng Sơn gets around 290 mm of rain over 37 wet days across fall. The line is the day-by-day chance of measurable precipitation.
Humidity in Fall
Most of fall feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Fall
Winds average 9 km/h across fall.
Sunrise & sunset in Fall
Daylight runs from about 12 h 24 min in early September to 10 h 48 min by late November. The lit band spans sunrise to sunset each day.
Solar energy in Fall
Average shortwave solar energy reaching the ground each day across fall, about 4.0 kWh/m².
Hazard calendar for Lạng Sơn
In fall, Lạng Sơn overlaps its monsoon season. The full year is below, with each hazard's peak months called out.
Lạng Sơn's monsoon runs May–September, when most of the year's rain falls.
Is fall a good time to visit Lạng Sơn?
Our two travel scores rate fall for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
fall is a reasonable time to visit Lạng Sơn for sightseeing.
What to pack for Lạng Sơn in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, Lạng Sơn sees daytime highs around 27°C and nights near 20°C. Pack light clothes and rain gear. About 37 days see rain.
UV index in Lạng Sơn in Fall
Clear-sky midday UV across fall averages around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Lạng Sơn peaks around June 23 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 14 at about 6 (high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 6 | 7 | 9 | 7 | 9 | 12 | 12 | 10 | 10 | 8 | 6 | 6 |
| Level | High | High | Very high | High | Very high | Extreme | Extreme | Extreme | Very high | Very high | High | High |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 6 | High |
| Feb | 7 | High |
| Mar | 9 | Very high |
| Apr | 7 | High |
| May | 9 | Very high |
| Jun | 12 | Extreme |
| Jul | 12 | Extreme |
| Aug | 10 | Extreme |
| Sep | 10 | Very high |
| Oct | 8 | Very high |
| Nov | 6 | High |
| Dec | 6 | High |
Air quality in Lạng Sơn in Fall
Average fine-particle pollution (PM2.5) through the year — so you can see where fall falls, not just the annual average.
Air quality in Lạng Sơn is worst in December — around 58 µg/m³ PM2.5 (unhealthy), about 2.3× the cleanest month (July, 25 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 57 | 55 | 55 | 54 | 37 | 29 | 25 | 29 | 36 | 43 | 50 | 58 |
| Level | Unhealthy | Unhealthy | Poor | Poor | Poor | Moderate | Moderate | Moderate | Poor | Poor | Poor | Unhealthy |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 57 | Unhealthy |
| Feb | 55 | Unhealthy |
| Mar | 55 | Poor |
| Apr | 54 | Poor |
| May | 37 | Poor |
| Jun | 29 | Moderate |
| Jul | 25 | Moderate |
| Aug | 29 | Moderate |
| Sep | 36 | Poor |
| Oct | 43 | Poor |
| Nov | 50 | Poor |
| Dec | 58 | Unhealthy |
Where is Lạng Sơn?
Lạng Sơn sits at 21.9°N, 106.8°E, 265 m above sea level, in Vietnam. The nearest listed city is Thị Trấn Na Dương, 26 km away.
Topography around Lạng Sơn
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Lạng Sơn.
Within 3 km, the terrain around Lạng Sơn has only modest variations in elevation — a maximum elevation change of 171 m around an average of 282 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 978 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,481 m.
The land around Lạng Sơn is covered by trees (46%) and artificial surfaces (32%) within 3 km, trees (80%) within 16 km, and trees (89%) within 80 km.
Vietnam travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type A / B / C / F
- 220 V · 50 Hz
- Prices
- ≈ 29% of US
- price level, 2025
- GDP per capita
- $5,066
- 2025
- Happiness
- 6.4 / 10
- World Happiness, 2025
- Safe drinking water
- 59%
- of population, 2024
- Homicide rate
- 1.5
- per 100k, 2011
- Road deaths
- 30.6
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- Moderate
- EF EPI 500
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Lạng Sơn (21.8526°, 106.761°, elevation 265 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.