What is the Ocean Viewing Index (OVI) for Ha Long Bay?

OVI is a 0-100 composite score combining sea color, water clarity, visibility, sea conditions, sunlight and water quality to help you decide if the sea is worth seeing today.

When is the best time to visit Ha Long Bay for sea views?

Start with the current and 7-day OVI forecast for Ha Long Bay, then choose a daylight period that also fits your plan. If you want tide pools, exposed shore, or a tide-dependent walk, check the local high and low tide times as well.

Should I use tide times or OVI for a visit to Ha Long Bay?

Use tide times when your visit depends on water level, such as a sandbar, tide pool, or exposed rocks. Use OVI to compare likely sightseeing conditions including sea appearance, visibility, sea state, and lighting. For a coastal trip, read both together.

Ha Long Bay Tides & Ocean Viewing Index

Quang Ninh, VietnamAsia/Ho_Chi_Minh

Ocean View Index

61Fair

Next tide

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Sunrise / Sunset

22:49 – 10:21

Local time

06:49

Ha Long Bay, a UNESCO World Natural Heritage site, enchants visitors with its emerald waters dotted by over a thousand karst islets.

Ocean Viewing Index

Updated · Oct 23, 2026 22:33

Reference time: local noon · 11:35 (Asia/Ho_Chi_Minh)

Estimated

Fair

Fair conditions. Sea color may appear muted.

Sub-Index Breakdown

Six dimensions feed the overall Ocean Viewing Index.

Sea Color
Clear blue-green · hue
76.6
Clarity
Very clear (below 1.5 NTU) · NTU
90.4
Visibility
Under 8 m · m
0.4
Sea State
Calm, glassy (0-1) · Beaufort
100
Lighting
Low / harsh light · lux
43.1
Water Quality
index
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Weather Forecast

7-day marine weather forecast from Open-Meteo model.

TodayOct 23

Light Rain

30°26°

1.7 m/s

1.7mm

SatOct 24

Light Rain

30°26°

2.6 m/s

0.5mm

SunOct 25

Light Rain

31°26°

2.8 m/s

0.2mm

MonOct 26

Light Rain

31°25°

3.6 m/s

0.5mm

TueOct 27

Light Rain

31°25°

3.8 m/s

0.6mm

WedOct 28

Light Rain

30°25°

4.0 m/s

0.8mm

ThuOct 29

Light Rain

28°25°

3.6 m/s

11.7mm

Visibility: 10 km·Cloud: 21%

48-Hour Hourly Forecast

Hour-by-hour marine weather for the next 48 hours.

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7-Day OVI Trend

Forecast ocean viewing conditions for the coming week.

Best on Tue: Viewing conditions are Excellent; aim for the golden hour just after sunrise or before sunset. Great for snorkeling and photography.

High & Low Tides Today

Times and heights of today's high and low water.

Mixed TideCoefficient: 77.6 / 120Higher coefficient means larger tide range; 120 is the largest spring, 20 the smallest neap.

Time	Type	Height
No tide extremes recorded today.

Fishing & Surf Forecast

Solunar feeding times and today's surf rating.

80Excellent0FlatView full forecast

48-Hour OVI Trend

Hour-by-hour ocean viewing outlook for the next 48 hours, dampened by rainfall.

Today's Tide Summary

A quick look at the day's high and low water.

Best Months to Visit

Average Ocean Viewing Index by month over the past year.

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Based on historical climatology (Pitarch 2021)

Nearby Beaches

Other beaches closest to Ha Long Bay.

551 km away

My Khe Beach

Da Nang, Vietnam

673 km away

Nam Van Lake

Macau Peninsula, Macau

675 km away

Hac Sa Beach

Coloane, Macau

676 km away

Cheoc Van Beach

Coloane, Macau

Frequently asked questions

What is the Ocean Viewing Index (OVI) for Ha Long Bay?: OVI is a 0-100 composite score combining sea color, water clarity, visibility, sea conditions, sunlight and water quality to help you decide if the sea is worth seeing today.
When is the best time to visit Ha Long Bay for sea views?: Start with the current and 7-day OVI forecast for Ha Long Bay, then choose a daylight period that also fits your plan. If you want tide pools, exposed shore, or a tide-dependent walk, check the local high and low tide times as well.
Should I use tide times or OVI for a visit to Ha Long Bay?: Use tide times when your visit depends on water level, such as a sandbar, tide pool, or exposed rocks. Use OVI to compare likely sightseeing conditions including sea appearance, visibility, sea state, and lighting. For a coastal trip, read both together.

Essential Information

Coordinates: 20.9101°, 107.1839°
Timezone: Asia/Ho_Chi_Minh
Region & Country: Quang Ninh, Vietnam

Data sources

Tides: UHSLC / FES2022b · Weather: NOAA GFS · Sea color: NASA MODIS/VIIRS