January in Ha Long Bay — middling scores, decent value
Trade-offs · 6.5/10January averages 17°C (62°F), the range most people find easiest for walking a city all day without either overheating or losing daylight to weather.
Rainfall runs 58 mm, so plan one flexible day in three; you still get about 2 days with 6+ hours of sunshine and 10.9 hours of daylight.
It scores 6.5/10 here, 5th of 12 months, against 8/10 in the destination's best month.
Figure on peak pricing, with crowds are moderate.
Pack layers you can shed by midday plus one warm layer for the evening, a packable rain layer, footwear you can get muddy.
Flexible dates? November scores 1.5 points higher here — enough to change the trip.
February in Ha Long Bay — workable with trade-offs
Trade-offs · 6.2/10February averages 17°C (63°F), the range most people find easiest for walking a city all day without either overheating or losing daylight to weather.
Rainfall runs 74 mm, so plan one flexible day in three; you still get about 3 days with 6+ hours of sunshine and 11.3 hours of daylight.
It scores 6.2/10 here, 7th of 12 months, against 8/10 in the destination's best month.
Figure on mid-season pricing, with crowds are moderate.
Pack layers you can shed by midday plus one warm layer for the evening, a packable rain layer, footwear you can get muddy.
Flexible dates? November scores 1.8 points higher here — enough to change the trip.
March in Ha Long Bay: strong conditions, 3rd of 12
Good · 7.5/10Trail conditions at 21°C (70°F) favour early starts and shaded routes in March; midday is for water breaks, not for exposed climbs.
Budget for roughly 50 mm of rain this month — a flexible day or two helps — with about 9 days with 6+ hours of sunshine and 11.9 hours of daylight to work around it.
That is 7.5/10 on the same scale — 3rd of 12 months, versus 8/10 for the best month here.
Expect peak pricing, and crowds are moderate. You are paying the year's highest rates for the year's best conditions — book early or shift a few weeks either side.
Pack light clothing, a hat and real sun protection, a packable rain layer, footwear you can get muddy.
April in Ha Long Bay — middling scores, decent value
Trade-offs · 6.8/10April averages 25°C (76°F) — warm for the outdoors: start trails early, use shaded routes at midday, and carry more water than you think you need.
Rainfall runs 60 mm, so plan one flexible day in three; you still get about 15 days with 6+ hours of sunshine and 12.5 hours of daylight.
It scores 6.8/10 here, 4th of 12 months, against 8/10 in the destination's best month.
Plan for mid-season pricing, with crowds are moderate.
Pack light clothing, a hat and real sun protection, a packable rain layer, footwear you can get muddy.
May in Ha Long Bay: expect compromises
Hardest · 4.2/10Days in May average 27°C (80°F) and humidity near 85% — front-load outdoor plans before the heat builds and treat the middle of the day as indoor time.
This is the year's wettest stretch at 246 mm, but with about 20 days with 6+ hours of sunshine it is not a total loss; an indoor fallback covers the risk.
That is 4.2/10 on the same scale — 8th of 12 months, versus 8/10 for the best month here.
Budget for low-season pricing, and crowds are light for this destination.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella, footwear you can get muddy.
If your dates are flexible, November is materially better in Ha Long Bay — 3.8 points higher on the same scale.
June in Ha Long Bay — the hardest end of the year
Hardest · 3.2/10June averages 29°C (83°F) and humidity near 89%, so the practical pattern is early mornings, a long midday break, and evenings back outside.
397 mm of rain puts this in monsoon territory — about 18 days with 6+ hours of sunshine across the whole month, and multi-day washouts are normal.
It scores 3.2/10 here, 10th of 12 months, against 8/10 in the destination's best month.
Plan for low-season pricing, with crowds are light for this destination.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella, footwear you can get muddy.
Flexible dates? November scores 4.8 points higher here — enough to change the trip.
July in Ha Long Bay — the hardest end of the year
Hardest · 3.7/10July averages 29°C (84°F) and humidity near 87%, so the practical pattern is early mornings, a long midday break, and evenings back outside.
333 mm makes this the wettest stretch of the year, though about 25 days with 6+ hours of sunshine still appear — keep an indoor fallback ready.
It scores 3.7/10 here, 9th of 12 months, against 8/10 in the destination's best month.
Figure on low-season pricing, with crowds are moderate.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella, footwear you can get muddy.
Flexible dates? November scores 4.3 points higher here — enough to change the trip.
August in Ha Long Bay — off-season conditions
Hardest · 3.1/10Days in August average 28°C (83°F) and humidity near 87% — front-load outdoor plans before the heat builds and treat the middle of the day as indoor time.
Expect monsoon-level rainfall at 415 mm: only about 17 days with 6+ hours of sunshine across the month, and stretches of heavy rain are normal.
That is 3.1/10 on the same scale — 11th of 12 months, versus 8/10 for the best month here.
Budget for low-season pricing, and crowds are light for this destination.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella, footwear you can get muddy.
If your dates are flexible, November is materially better in Ha Long Bay — 4.9 points higher on the same scale.
September in Ha Long Bay: expect compromises
Hardest · 3/10Days in September average 28°C (82°F) and humidity near 85% — front-load outdoor plans before the heat builds and treat the middle of the day as indoor time.
Expect monsoon-level rainfall at 459 mm: only about 15 days with 6+ hours of sunshine across the month, and stretches of heavy rain are normal.
That is 3/10 on the same scale — 12th of 12 months, versus 8/10 for the best month here.
Expect low-season pricing, and crowds are light for this destination.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella, footwear you can get muddy.
If your dates are flexible, November is materially better in Ha Long Bay — 5 points higher on the same scale.
October in Ha Long Bay — middling scores, decent value
Trade-offs · 6.3/10October averages 24°C (76°F) — warm for the outdoors: start trails early, use shaded routes at midday, and carry more water than you think you need.
Rainfall runs 90 mm, so plan one flexible day in three; you still get about 17 days with 6+ hours of sunshine and 11.5 hours of daylight.
It scores 6.3/10 here, 6th of 12 months, against 8/10 in the destination's best month.
Plan for mid-season pricing, with crowds are moderate.
Pack light clothing, a hat and real sun protection, a packable rain layer, footwear you can get muddy.
Flexible dates? November scores 1.7 points higher here — enough to change the trip.
November in Ha Long Bay — the year's strongest window
Best window · 8/10November averages 22°C (72°F) — warm for the outdoors: start trails early, use shaded routes at midday, and carry more water than you think you need.
Expect 33 mm of rain — occasional showers rather than washed-out days — alongside about 12 days with 6+ hours of sunshine and 11 daylight hours.
On our climate-comfort scale this is the top-ranked month of the year for Ha Long Bay at 8/10 — the reference point every other month on this page is measured against.
Figure on peak pricing, with this is one of the busiest months here. You are paying the year's highest rates for the year's best conditions — book early or shift a few weeks either side.
Pack light clothing, a hat and real sun protection, footwear you can get muddy.
December holds up well in Ha Long Bay — 2nd best month
Good · 7.8/10Temperatures hover around 17°C (62°F) — the kind of month where neither heat nor cold forces the schedule.
At just 7 mm for the month, rain will not shape your plans; you get about 6 days with 6+ hours of sunshine and 10.7 hours of daylight.
That is 7.8/10 on the same scale — 2nd of 12 months, versus 8/10 for the best month here.
Expect peak pricing, and this is one of the busiest months here. You are paying the year's highest rates for the year's best conditions — book early or shift a few weeks either side.
Pack layers you can shed by midday plus one warm layer for the evening, footwear you can get muddy.
