Will you see Ha Long Bay? Clear-view odds by month
Short answer: Ha Long Bay is most likely to be visible in July, when 79% of afternoons are free of low cloud and fog, and least likely in March (32%). Afternoons are usually clearer than mornings.
Winter and spring often bring mist over the karsts; summer is clearer but has storms.
How often the view from a cruise deck is clear
| Month | Clear mornings (7–9 am) | Clear afternoons (2–4 pm) | Overcast mornings |
|---|---|---|---|
| January | 30% | 40% | 48% |
| February | 25% | 34% | 61% |
| March | 20% | 32% | 64% |
| April | 33% | 46% | 40% |
| May | 48% | 60% | 14% |
| June | 65% | 76% | 7% |
| July | 63% | 79% | 5% |
| August | 64% | 69% | 6% |
| September | 67% | 75% | 8% |
| October | 69% | 70% | 8% |
| November | 56% | 69% | 18% |
| December | 50% | 55% | 31% |
Tours
Questions
What is the best month to see Ha Long Bay?
Ha Long Bay is most likely to be visible in July, when 79% of afternoons are free of low cloud and fog, and least likely in March (32%). Afternoons are usually clearer than mornings.
Is Ha Long Bay clearer in the morning or the afternoon?
Afternoons: in 11 of 12 months the sky is clear more often between 2 and 4 pm. Morning cloud and fog often lift by midday.
How often is Ha Long Bay hidden by cloud?
In March, 64% of mornings are overcast; in July only 5%. Winter and spring often bring mist over the karsts; summer is clearer but has storms.
Share of days from 2016-2025 when low cloud (including fog) averaged under 30% in the given hours, from ERA5 reanalysis (Copernicus) via Open-Meteo, on a ~25 km grid around Quang Ninh, Vietnam. Peaks can make their own cloud that the grid misses; check a webcam on the day.