How we work out the status
Every hour we fetch the weather forecast for each pass and town, at its own altitude, and compare it with fixed limits. The worst signal sets the status.
Unknown is never green. If any data is missing or older than 6 hours, the status is yellow with the label “Data not up to date”.
Official landslide and flash-flood warnings, and road events checked by our admin, can only raise the status. Only an admin can lower it, with a note, a source and an end time, and never while the weather itself is red.
Forecasts for today and the next 2 days have high confidence, days 3–4 medium, days 5–7 low: read those as a trend only.
Green means favourable weather, nothing more. Mountain roads change fast. Always check official warnings and ask locals before you ride.
Limits we use
| Signal | Take care from | Consider postponing from |
|---|---|---|
| Rain, past 72 hours | ≥ 50 mm | ≥ 100 mm |
| Rain, next 24 hours | ≥ 20 mm | ≥ 50 mm |
| Heaviest shower, 6:00–18:00 | ≥ 5 mm/h | ≥ 15 mm/h |
| Lowest visibility, 6:00–18:00 | < 1000 m | < 200 m |
| Strongest gust, 6:00–18:00 | ≥ 40 km/h | ≥ 60 km/h |
| Lowest temperature | ≤ 5 °C | ≤ 1 °C |
| Storm energy (CAPE) while raining | ≥ 1000 J/kg | — |
Starting values that lean cautious. We will adjust them against real events and say so here.
Data sources
- Weather data: Open-Meteo (CC BY 4.0)
- Map: roads © OpenStreetMap contributors (ODbL); relief from the Copernicus DEM
- Official landslide and flash-flood warnings: luquetsatlo.nchmf.gov.vn
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