Ha Long in Summer
In summer (June, July and August), Ha Long sees average daytime highs around 31°C and overnight lows near 26°C, with 952 mm of rain over about 73 wet days across the season. It is the warmest season of the year and the wettest season of the year.
Across summer, daytime highs hold fairly steady around 31°C. The sky is clear or mostly clear about 9% of the time across summer, and the air most often feels miserable.
Summer is Ha Long's weakest season of the year to visit on our travel score. For the whole year in context, see Ha Long's year-round climate.
- Avg daytime high
- 31°C
- warmest season of the year
- Avg overnight low
- 26°C
- Rainfall
- 952 mm
- 73 wet days
- Avg wind
- 10 km/h
- Travel score
- 2.8
- weakest season of the year
- Months
- Jun · Jul · Aug
Temperature in Ha Long in Summer
Across summer, daytime highs hold fairly steady around 31°C.
A typical summer day in Ha Long reaches about 31°C and drops to 26°C overnight. The warmest of the three months is June, the coolest August.
How summer really feels in Ha Long
Once humidity and wind are folded in, summer brings about 92 days that feel above 32°C and 0 that feel at or below 0°C.
The story in summer is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Ha Long weather by month
How the three summer months (June, July and August) 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 | 19° / 15° | 34 | 6.5 | 10.9 | 6.3 |
| Feb | 20° / 16° | 21 | 5.6 | 11.3 | 6.4 |
| Mar | 22° / 18° | 44 | 8.8 | 11.9 | 6.5 |
| Apr | 26° / 22° | 69 | 11.6 | 12.5 | 6.0 |
| May | 30° / 25° | 219 | 19.5 | 13 | 3.9 |
| Jun | 31° / 27° | 266 | 22.4 | 13.2 | 2.9 |
| Jul | 31° / 27° | 305 | 24.3 | 13.1 | 2.8 |
| Aug | 31° / 26° | 381 | 26.2 | 12.7 | 2.7 |
| Sep | 30° / 25° | 243 | 20 | 12.1 | 3.6 |
| Oct | 28° / 23° | 104 | 11.9 | 11.5 | 5.7 |
| Nov | 25° / 19° | 51 | 8.2 | 11 | 7.1 |
| Dec | 21° / 16° | 31 | 5.9 | 10.8 | 7.0 |
Cloud cover in Summer
The sky is clear or mostly clear about 9% of the time across summer.
Chance of precipitation in Summer
Ha Long gets around 952 mm of rain over 73 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels miserable — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 10 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 13 h 12 min in early June to 12 h 24 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 4.9 kWh/m².
Hazard calendar for Ha Long
In summer, Ha Long overlaps its pacific typhoon and monsoon season. The full year is below, with each hazard's peak months called out.
Ha Long sits in the Pacific typhoon belt; the season peaks July–October.
Ha Long's monsoon runs May–September, when most of the year's rain falls.
Is summer a good time to visit Ha Long?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a weaker month for outdoor sightseeing in Ha Long.
What to pack for Ha Long in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Ha Long sees daytime highs around 31°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 73 days see rain.
Sea temperature near Ha Long in Summer
The nearest coast averages about 29°C across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 32 km away) is warmest in August at about 30°C and coldest in February near 19°C.
It's comfortable for a long swim from Mar 13 to Jan 10 — about 10 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 20 | 19 | 20 | 23 | 27 | 29 | 29 | 30 | 29 | 28 | 25 | 22 |
| Comfort | Cool | Cool | Refreshing | Refreshing | Warm | Tropical | Tropical | Tropical | Tropical | Warm | Warm | Refreshing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 20 | Cool |
| Feb | 19 | Cool |
| Mar | 20 | Refreshing |
| Apr | 23 | Refreshing |
| May | 27 | Warm |
| Jun | 29 | Tropical |
| Jul | 29 | Tropical |
| Aug | 30 | Tropical |
| Sep | 29 | Tropical |
| Oct | 28 | Warm |
| Nov | 25 | Warm |
| Dec | 22 | Refreshing |
UV index in Ha Long in Summer
Clear-sky midday UV across summer averages around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Ha Long peaks around July 12 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 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) | 7 | 8 | 9 | 8 | 10 | 12 | 12 | 9 | 9 | 9 | 7 | 6 |
| Level | High | Very high | Very high | Very high | Extreme | Extreme | Extreme | Very high | Very high | Very high | High | High |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 7 | High |
| Feb | 8 | Very high |
| Mar | 9 | Very high |
| Apr | 8 | Very high |
| May | 10 | Extreme |
| Jun | 12 | Extreme |
| Jul | 12 | Extreme |
| Aug | 9 | Very high |
| Sep | 9 | Very high |
| Oct | 9 | Very high |
| Nov | 7 | High |
| Dec | 6 | High |
Air quality in Ha Long in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.
Air quality in Ha Long is worst in January — around 42 µg/m³ PM2.5 (poor), about 2.6× the cleanest month (July, 16 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) | 42 | 42 | 41 | 40 | 26 | 19 | 16 | 18 | 21 | 27 | 29 | 39 |
| Level | Poor | Poor | Poor | Poor | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Poor |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 42 | Poor |
| Feb | 42 | Poor |
| Mar | 41 | Poor |
| Apr | 40 | Poor |
| May | 26 | Moderate |
| Jun | 19 | Moderate |
| Jul | 16 | Moderate |
| Aug | 18 | Moderate |
| Sep | 21 | Moderate |
| Oct | 27 | Moderate |
| Nov | 29 | Moderate |
| Dec | 39 | Poor |
Where is Ha Long?
Ha Long sits at 21.0°N, 107.1°E, 8 m above sea level, in Vietnam. The nearest listed city is Cẩm Phả, 22 km away.
Topography around Ha Long
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Ha Long.
Within 3 km, the terrain around Ha Long has only modest variations in elevation — a maximum elevation change of 150 m around an average of 9 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 679 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,530 m.
The land around Ha Long is covered by water (57%) and artificial surfaces (21%) within 3 km, water (46%) and trees (37%) within 16 km, and trees (42%) and water (42%) 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 Ha Long (20.9505°, 107.0734°, elevation 8 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.