Hạ Long climate
Hạ Long (Vietnam) has a monsoon-influenced humid subtropical climate (Köppen Cwa). The average temperature over the year is 24 °C75 °F, and about 1,643 mm65 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Hạ Long climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin |
|---|---|---|---|---|
| Jan | 2068 | 1254 | 1661 | 391.5 |
| Feb | 2272 | 1458 | 1865 | 251.0 |
| Mar | 2577 | 1763 | 2170 | 502.0 |
| Apr | 2883 | 2170 | 2576 | 692.7 |
| May | 3087 | 2576 | 2882 | 1686.6 |
| Jun | 3188 | 2780 | 2984 | 2138.4 |
| Jul | 3188 | 2780 | 2984 | 30212 |
| Aug | 3187 | 2680 | 2983 | 33813 |
| Sep | 3087 | 2577 | 2882 | 2409.4 |
| Oct | 2883 | 2272 | 2577 | 1224.8 |
| Nov | 2578 | 1865 | 2271 | 512.0 |
| Dec | 2170 | 1456 | 1763 | 271.1 |
| Year | 3188 | 1254 | 2475 | 1,64365 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 79% | 76% | 2.5 | 10:59 |
| Feb | 81% | 80% | 2.8 | 11:26 |
| Mar | 82% | 83% | 3.0 | 11:59 |
| Apr | 82% | 76% | 4.2 | 12:36 |
| May | 84% | 73% | 5.2 | 13:07 |
| Jun | 86% | 83% | 5.3 | 13:24 |
| Jul | 86% | 80% | 5.2 | 13:17 |
| Aug | 86% | 80% | 4.8 | 12:50 |
| Sep | 83% | 71% | 4.7 | 12:14 |
| Oct | 80% | 57% | 4.3 | 11:38 |
| Nov | 79% | 58% | 3.5 | 11:07 |
| Dec | 76% | 69% | 2.7 | 10:52 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Hạ Long is like
The warmest month is July, with an average high of 31 °C88 °F and a low of 27 °C80 °F. The coldest is January, when highs average 20 °C68 °F and lows 12 °C54 °F. There is a clear seasonal cycle, with 12.5 °C22.5 °F between the average temperature of the warmest and the coolest month.
It is wet, with about 1,643 mm65 in of precipitation per year. The wettest three-month stretch is July–September, which brings 53% of the annual total. The wettest month is August (338 mm13 in), the driest is February (25 mm1.0 in).
Relative humidity ranges from 76% in December to 86% in June. The clearest skies (lowest average cloud amount, 57%) are typical of October. Average wind speed near the ground ranges from 7 km/h (4 mph) in August to 10 km/h (6 mph) in December. Daylight lasts from about 10.9 hours in December to 13.4 hours in June.
Best time to visit Hạ Long
Based on these averages, the most comfortable months for sightseeing and outdoor activities are November–March: average highs of 20 °C68 °F to 25 °C78 °F with 25 mm1.0 in to 51 mm2.0 in of precipitation per month.
The most challenging month is August, which is hot, with average highs of 31 °C87 °F, very wet (338 mm13 in) and humid (86% relative humidity).
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Hạ Long
- Wetter months (May–September) — highs 3087 to 31 °C88 °F, lows 2576 to 27 °C80 °F, about 252 mm9.9 in of precipitation a month. Pack very light, breathable clothing, a sun hat and plenty of water and a good rain jacket or umbrella and quick-drying shoes.
- Drier months (October–April) — highs 2068 to 28 °C83 °F, lows 1254 to 22 °C72 °F, about 55 mm2.2 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses.
How Hạ Long compares
Compared with Haiphong, about 42 km to the west, Hạ Long has practically the same average temperature and receives a similar amount of precipitation.
Of the 75 places in Vietnam covered by World Climates, Hạ Long is the 58th warmest by annual mean temperature and the 22nd wettest by annual precipitation. See all of them on the Vietnam climate page.
Places in other countries with the most similar temperature and rainfall pattern: Beihai (China, Cwa), Dongxing (China, Cwa) and Maoming (China, Cfa).
Nearby places
- Cẩm Phả 22 km · 24 °C75 °F · 1,671 mm66 in
- Haiphong 42 km · 24 °C75 °F · 1,643 mm65 in
- Chũ 71 km · 23 °C74 °F · 1,498 mm59 in
- Hải Dương 77 km · 24 °C75 °F · 1,616 mm64 in
- Bắc Giang 98 km · 24 °C74 °F · 1,549 mm61 in
- Lạng Sơn 105 km · 22 °C71 °F · 1,350 mm53 in
- Bắc Ninh 107 km · 24 °C75 °F · 1,616 mm64 in
- Nam Định 109 km · 24 °C75 °F · 1,637 mm64 in
Frequently asked questions
What is the warmest month in Hạ Long?
July is the warmest month in Hạ Long, with an average high of 31 °C (88 °F) and an average low of 27 °C (80 °F).
What is the coldest month in Hạ Long?
January is the coldest month, with an average high of 20 °C (68 °F) and an average low of 12 °C (54 °F).
When does it rain the most in Hạ Long?
August is the wettest month with about 338 mm (13.3 in) of precipitation; February is the driest with about 25 mm (1.0 in).
What is the best time to visit Hạ Long?
Judging by long-term averages, the most comfortable months are November–March.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 100 m, while Hạ Long lies at about 8 m. Temperatures on this page were therefore adjusted by +0.6 °C1.1 °F using the standard lapse rate of 6.5 °C per 1,000 m.