Dinh Gio, Ta Xua
Ta Xua, Son La
Made for mountain motorbike riders in Northern Vietnam
Know before sunrise if the sea of clouds will form
See the daily sea-of-clouds probability for each cloud spot, community road reports from riders on the passes, and keep track of your group while riding.
31Cloud spots tracked across 10 regions
3 daysDaily forecasts: tomorrow, the day after, and the day after that
3 hoursForecasts refreshed every 3 hours
2 tapsTo send a road report
CLOUD SPOTS
Cloud spots we track
A few highlights from the 31 tracked spots. See each day’s probability right here on the web or in the app. Coordinates and elevations are approximate and are being verified on the ground.
Pha Luong
Moc Chau, Son La
O Quy Ho Pass
Sa Pa, Lao Cai
Y Ty
Bat Xat, Lao Cai
Ma Pi Leng - Tham Ma
Ha Giang
Quan Ba Heaven Gate
Ha Giang
Khau Pha Pass
Mu Cang Chai, Yen Bai
REAL REELS
Reels & Authentic Rider Moments
Vibrant short video clips captured by adventurous motorbike riders across Northern Vietnam.
FEATURES
What is inside the app
Built for mountain motorbike trips: readable at a glance and usable with gloves on.
Daily cloud forecast
Sea-of-clouds probability for tomorrow, the day after and the day after that, always with forecast confidence and how far the cloud top sits below the viewpoint.
Cloud spot map
Cloud spots on a map, colored by probability and always labeled in text so they are readable outdoors.
Road reports
Riders report fog, slippery roads and landslides. Reports take a few taps and expire so stale news does not linger.
Riding groups
Create or join a group with an invite code, share your location while you choose to, and get alerts when someone falls far behind or loses signal.
TRANSPARENCY
Data transparency principles
We value your safety and your time on every mountain curve.
- Probability and confidence are different things and are always shown together.
- When data is missing the app says "No forecast yet", never 0%.
- Forecasts are daily, up to 3 days; no fake minute-by-minute charts.
- Fog and landslide reports come from riders on the road, with no ads or tour promotions mixed in.
Safety comes first
Cloud forecasts and community road reports are for reference only. Weather on mountain passes can change within minutes; always stay in control, slow down in fog and observe real conditions.
In danger on the road: call 112 (national emergency number).
FAQ
Frequently asked questions about Mây Đèo
Answers to common questions from riders who hunt for clouds.
When is the sea of clouds most likely to appear?
It is more common in the cooler season, especially at dawn after light rain when humidity is high and wind is weak. This is general knowledge; check the daily probability for each spot in the app.
How does Mây Đèo calculate probability?
The app takes weather forecasts (cloud layers, humidity by altitude, wind, temperature), scores each spot against its own thresholds and shows the probability with a confidence level. It is an estimate, not a promise.
Does the app work without a signal?
Without a signal the app shows the last saved forecast with its update time, and reports you send are kept on your phone and resent when you are back online. The map does not work offline yet.
How do I report a road condition?
Stop somewhere safe, open the Road reports tab, choose the pass, the type of hazard and its severity, then send. A description and a photo are optional.