Trip verdict
Will it rain on your road,
where, and when?
A normal weather app tells you about one place. A road trip passes through many places over several hours, so Rain on Route checks each stretch of road at the hour you will actually be on it.
Your start, any stops and your destination are turned into map points, and the road route between them is fetched from OSRM, an open routing service built on OpenStreetMap.
Points are placed along the road roughly every 25 km, up to 25 points for long trips, so no stretch is skipped.
Chennai → Madurai, 456 km → 20 milestones
Arrival time at each milestone comes from your departure time and the slower of your vehicle's speed and the route's average speed.
Two-wheeler 45 km/h · Car 70 km/h · Bus 50 km/h
One request asks Open-Meteo for the hourly forecast at every milestone. Only the hour you arrive is used. Three independent weather models (ECMWF, GFS and ICON) are compared to see if they agree. Milestones you reach in the next 90 minutes use a 15-minute forecast instead.
Each milestone gets a rain level from the millimetres expected in that hour. The share of wet milestones gives the verdict, and the worst stretch is named with its place and time.
"Rain on parts of the route. Heavy rain near Villupuram around 3:10 pm."
| Level | Rain in that hour |
|---|---|
| Dry | < 0.2 mm |
| Light | 0.2 – 2.5 mm |
| Moderate | 2.5 – 7.5 mm |
| Heavy | > 7.5 mm |
Rain is rain: any level from Light up counts as wet, the same for a bike, car or bus. Dry = no rain at any milestone. Mostly dry = under 25% wet. Rain on parts = 25–60%. Rainy trip = over 60%, or more than 50 km of heavy rain in a row.