December brings 20°C daytime highs, 32mm of precipitation across about 2 wet days and 10.7 hours of daylight — best for hiking and cycling. The strongest run of the year is November to January. August is the quietest month: wetter, but peaceful, and still good for green season and quiet and local.
Long-run climate normals for Ha Long Bay. Month ratings compare months within Ha Long Bay only — they are not a ranking of Ha Long Bay against other destinations, and they are not a forecast for a specific year.
Last updated: · Live forecast data refreshes hourly.
| Best month | December — Hiking, Cycling |
| Best 3-month window | November–January |
| Quietest month | August — Wetter, but peaceful |
| Driest month | January — 22mm |
| Wettest month | August — 310mm |
| Warmest / coolest | July 33°C / February 18°C |
| Seasonality | Strongly seasonal — the months feel like different places |
| Annual rainfall | 1745mm over roughly 118 rain days |
August gets roughly 869% more precipitation than December — 310mm against 32mm. That difference, more than temperature, is what changes how a day here feels.
Daytime highs only move 15°C across the whole year (18–33°C), so timing matters far less here than rainfall does.
June gives you 13.3 hours of daylight against just 10.7 in December — a 3-hour difference in how much you can actually fit into a day.
January is the driest month at 22mm across roughly 2 wet days, while August peaks at 310mm.
November is almost as good as December, but usually quieter and cheaper. If your dates are flexible, it is the easier trip.
Ha Long Bay changes character completely through the year — December and August are effectively two different destinations. Pick the month that matches what you want to do, not the highest-rated one.
Ratings compare months within Ha Long Bay, not against destinations worldwide: five stars means the best time to be here, not that Ha Long Bay beats anywhere else. Tags describe what the conditions actually suit.
| Month | Rating | High / Low | Precipitation | Wet days | Sun | Daylight | Best for |
|---|---|---|---|---|---|---|---|
| January | ★★★★★ | 18°C / 13°C | 22mm | 2 | 5h | 10.9h | Hiking · Cycling |
| February | ★★★★★ | 18°C / 13°C | 28mm | 2 | 5h | 11.3h | Hiking · Cycling |
| March | ★★★★★ | 20°C / 15°C | 42mm | 3 | 5h | 11.9h | Hiking · Cycling · Spring greenery |
| April | ★★★★★ | 24°C / 17°C | 85mm | 6 | 6h | 12.5h | Hiking · Cycling |
| May | ★★★☆☆ | 27°C / 21°C | 180mm | 13 | 6h | 13h | Beach days · Swimming |
| June | ★★☆☆☆ | 31°C / 23°C | 225mm | 16 | 7h | 13.3h | Beach days · Swimming · Green season |
| July | ★★☆☆☆ | 33°C / 25°C | 265mm | 19 | 5h | 13.1h | Green season · Quiet and local |
| August | ★★☆☆☆ | 33°C / 25°C | 310mm | 22 | 5h | 12.7h | Green season · Quiet and local |
| September | ★★☆☆☆ | 31°C / 23°C | 245mm | 17 | 5h | 12.1h | Green season · Quiet and local |
| October | ★★★☆☆ | 27°C / 21°C | 165mm | 12 | 4h | 11.5h | Beach days · Swimming |
| November | ★★★★★ | 24°C / 17°C | 72mm | 5 | 9h | 11h | Hiking · Cycling · Reliable sunshine |
| December | ★★★★★ | 20°C / 15°C | 32mm | 2 | 8h | 10.7h | Hiking · Cycling |
| You are planning | Pick | Why |
|---|---|---|
| Sun & beach days | December | 8h daily sunshine, 20°C highs and only 2 rain days. |
| City walking & sightseeing | December | 20°C highs with 10.7h of daylight — long days without heat fatigue. |
| Photography & light | December | 8h of sun and 10.7h daylight give the widest window for golden-hour work. |
| Value & fewer crowds | February | Scores 77/100 — close to peak conditions but outside the busiest window. |
| Cooler-weather travel | January | 18°C highs and 13°C nights suit anyone who dislikes heat. |
Each month in Ha Long Bay is described from long-run climate normals and then rated relative to the other eleven months in the same city. A five-star January in a cold destination means January is one of the best times to be there — not that it beats a Mediterranean summer.
| Factor | Weight | What it measures |
|---|---|---|
| Temperature | Described | Average daytime high and overnight low for the month, shown as measured rather than judged. |
| Precipitation | Described | Monthly millimetres and wet-day count, labelled as snow or rain/snow where temperatures make that the likely phase. |
| Sunshine & daylight | Described | Average daily sunshine hours and astronomical daylight length at mid-month, from the city’s latitude. |
| “Best for” tags | Derived | Applied only when the conditions genuinely support the activity — snow depth-friendly cold for skiing, 13–24°C and low rain risk for hiking, dark evenings at high latitude for aurora. A month with few strong use cases gets fewer tags rather than padded ones. |
| Star rating | Relative | Ranks the month against the other eleven months in the same city. Never a comparison between cities. |
Figures are long-run climate averages, not a forecast for a specific year. Where a month lacks sourced rainfall or humidity, the value is modelled from temperature range and rain frequency.
December is the best all-round month in Ha Long Bay: 20°C highs, 32mm of precipitation and 10.7 hours of daylight, which suits hiking and cycling. The strongest three-month window is November to January.
August — 33°C highs, 310mm of precipitation over roughly 22 days and 12.7 hours of daylight. It is the cheapest and least crowded time to go, and it still works for green season and quiet and local.
January is the driest month at 22mm over about 2 rain days, against 310mm in August. Across the year Ha Long Bay records around 1745mm.
Yes, but the months are genuinely different trips. December suits hiking and cycling, while August suits green season and quiet and local. Pick the month that matches what you want to do.
Daylight ranges from 10.7 hours in December to 13.3 hours in June, calculated from the city's latitude.