open data
Halong Bay data: the files behind this guide
This guide to Halong Bay, Vietnam publishes four datasets as JSON files you can download: the Halong Bay storm stop log, the official sightseeing routes with their fees, the monthly storm and weather table, and the headline trip costs. Each file names its sources and carries the dates it rests on; how to cite and reuse them is at the foot of the page.
files
The four Halong Bay data files
One card per file: what it holds, where it comes from, when its sources were last read, and the download. The same data reads as a page on the guide; the link at the foot of each card goes there.
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Halong Bay storm stop log
Every storm or tropical depression that stopped Halong Bay tourist boats, as the Ha Long Bay Management Board posted it: 8 stops from September 2024 to August 2026. Start from the board's notice, end from Vietnam's final national storm bulletin or a reopening notice.
Fields in the file
- id and storm (number, name, season)
- bays and routes affected
- start: date and hour of the notice, local time (UTC+7)
- end: final national bulletin or reopening notice, with the rule that set it
- issuing body, document and source links
- the matching IBTrACS track
Read as a page: the storm stop log
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Official sightseeing routes and fees
The sightseeing routes boats may sail: Halong Bay's routes as the Ha Long Bay Management Board lists them, Bai Tu Long Bay's routes under Quang Ninh Decision 2119/QD-UBND, and Lan Ha Bay's 2020 list kept as history. 25 routes in all, each fee with its issuing body.
Fields in the file
- route code and name
- bay
- ports and stops in order
- whether boats may stay overnight
- each fee as a register row: value, unit, issuing body, source link, document date
- Lan Ha Bay routes marked as history
Read as a page: the official routes
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Storms, fog, rain and temperature by month
One row per month: storm and tropical depression tracks near the bay over 1991 to 2025, fog, rain and temperature at the nearest weather stations over 1996 to 2024, and the stops posted in that month.
Fields in the file
- storm tracks within the near and the far radius of the bay, and the years with one
- posted storm stops in the month
- fog days at Phu Lien and Bach Long Vi
- rain and rain days at Phu Lien
- mean and maximum temperature at Phu Lien
- the method and its sources (basis)
Read as a page: Halong Bay weather by month
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Headline trip costs
The 10 scenarios behind the headline costs this guide prints, from a night on board to the e-visa, each one amount with its parts, so a figure quoted from any page can be traced.
Fields in the file
- id and label (who it is for)
- amount in VND
- about the same in USD, AUD and GBP
- the parts and the register rows or listings behind each
- the page that prints it
Read as a page: Halong Bay cruise prices
method
How each file is built
The storm stop log
Each entry starts from a notice posted by the Ha Long Bay Management Board and ends with the final national storm bulletin, or a reopening notice where the board posted one. The board published 7 notices of storm or tropical depression stops between June 2025 and November 2026, and one reopening notice, after Typhoon Yagi in 2024. New stops are added as the board posts them. The full table with every hour is on the storm stop log page.
Routes and fees
The Ha Long Bay Management Board lists 8 routes on Halong Bay, each with its visitor fee. The file names each fee as a register row with its issuing body, document date and source link, and leaves out any fee that is not confirmed. The official routes page draws every route on a map.
Storms and weather by month
Storm counts come from NOAA's IBTrACS archive of Western Pacific best tracks; the saved subset around the Gulf of Tonkin holds 596 tropical systems. Fog, rain and temperature come from NOAA's Global Summary of the Day for the nearest synoptic stations, with saved data running to 24 August 2025. Official 1991 to 2020 climate normals for Bai Chay do not exist in the WMO set archived by NOAA: its count of Vietnamese stations is 0 stations. So the table names a station on every value, never "Halong Bay" as a whole. The Halong Bay weather page shows the table month by month.
Headline costs
Each cost is one definition, built from partner listings with their read dates and from fee and fare rows, and converted to US, Australian and British money with the State Bank of Vietnam rates explained on the money and e-visa page.
limits
What the files do not show
- Lan Ha Bay stops. Hai Phong's stop notices are not collected yet, so the storm stop log says nothing about how often Lan Ha Bay cruises stop.
- Squall holds. Same-day holds for thunderstorms and squalls are not posted as notices, so they are not in the log. The log is a floor, not a full count.
- Lan Ha Bay routes. The 2020 Hai Phong route list is in the routes file as history only: the rules that replaced it list no routes.
- Odds. The monthly storm counts are history. The storm odds pages build from them are a model, not a forecast, and no file says a cruise will run.
- Prices. Listing prices in the costs file are as read on the date given and change often; check the listing before you quote one as current.
citing
Citing and reusing the data
License for all four files: CC BY 4.0. A link to the file or the page a figure comes from lets your readers check it.
When you cite a file, give the dataset name, the file address, and the date you downloaded it, since the log and the costs change. The files are plain JSON with a dataset block at the top that holds the name, description and coverage, and each dataset is also described in the page's structured data. For questions or a correction, see about this guide.
Sources
- The Ha Long Bay Management Board states the number of sightseeing routes (hành trình) on Halong Bay as 8 routes. Ha Long Bay Management Board (halongbay.com.vn), fee page listing the 8 Halong Bay routes, 31 March 2025.
- Storm-track counts by month for the Gulf of Tonkin can be built from IBTrACS v04r01 (NOAA NCEI) Western Pacific best tracks; the saved subset covers 17-23N, 105-110E and holds a count of systems of 596 tropical systems. NOAA NCEI, International Best Track Archive for Climate Stewardship (IBTrACS) v04r01, WP basin CSV, file dated 2026-11-12, 12 November 2026.
- Daily fog flags, visibility, rain and temperature for the nearest synoptic stations (Phu Lien in Hai Phong, Bach Long Vi offshore, Mong Cai) are in NOAA's Global Summary of the Day; saved years run 1996 to the data end date 24 August 2025. NOAA NCEI, Global Summary of the Day (GSOD), stations 48826099999, 48839099999, 48838099999, 24 August 2025.
- Viet Nam is not among the countries in the WMO 1991-2020 Climatological Standard Normals archived by NOAA NCEI (accession 0253808), so official 1991-2020 normals for Bai Chay are not available from that dataset; Vietnam station count in it is 0 stations. NOAA NCEI, WMO Climatological Standard Normals 1991-2020, accession 0253808, Region II folders (versions 1.1 and 6.6), 14 November 2026.
- The Ha Long Bay Management Board website published seven storm or tropical depression suspension notices between June 2025 and November 2026 and one reopening notice (after Typhoon Yagi, 2024); the count of suspension notices is 7 notices. Ha Long Bay Management Board website, full post index ids 1-1365 read 2026-11-14, 14 November 2026.
- Published datasets. The JSON files under /data/, built from data/suspensions.json, data/routes.json, data/season.json and src/lib/scenarios.ts
- Storm odds and weather by month. Storm tracks: NOAA NCEI IBTrACS v04r01, seasons 1991 to 2025, systems within 150 km to 350 km of Halong Bay; a stop counted as 2 days from the board notice to the final national bulletin. Weather: NOAA Global Summary of the Day, Phu Lien (Hai Phong) and Bach Long Vi, 1996 to 2024; sea surface temperature: NOAA OISST v2.1, the grid cell south of Cat Ba Island, 1991 to 2020. Stop log: Ha Long Bay Management Board notices and the national final storm bulletins (data/suspensions.json).