About
Know before you go.
The Trail Guide helps hikers, mountain bikers and trail runners see — before they set out — whether a trail is likely to be dry, moist, snowy, or closed. It blends weather modelling, terrain analysis, and real field observations into a single map.
What it is
Trail conditions make or break a day out. A route that's perfect in the dry can turn into slippery, damaging mud after rain — and it's hard to know from home. The Trail Guide estimates the current and near-future state of each trail segment so you can pick the right route for the day, and avoid tearing up trails when they're too wet.
The current focus is the Swiss Alps, with the underlying engine designed to scale across the wider European trail network.
How the estimate is built
Each trail is split into short segments, and every segment carries two kinds of information:
- Terrain that doesn't change — slope, aspect (which way it faces the sun), forest cover, soil type and clay content, and how well it drains. This comes from open elevation, land-cover and soil datasets.
- Weather that does change — recent and forecast rain, temperature and snow, pulled daily from a self-hosted weather model (Open-Meteo: ICON-EU forecast plus ERA5-Land history).
From these, the model computes a wetness score for every segment, updated daily, for both current conditions and a +24-hour forecast. Snow, ice and official closures are handled separately on top.
Calibrated with real photos & observations
A model is only as good as its grounding in reality. The dry-vs-moist line is calibrated against tens of thousands of geotagged trail photos from across Switzerland, read by a small on-device vision model that judges whether a trail surface looks dry, moist, or snowy. Coming soon: riders, walkers and runners will be able to log what they actually found on the ground — each observation becoming a training sample that sharpens future versions.
Who's behind it
The Trail Guide is an independent project, built out of a love for the mountains and a genuine curiosity for how the elements impact these places and its users. It runs on self-hosted hardware, uses open data, and credits every source. New regions and features are added as time (and support) allow.
Where it's going
A high-level look at what's planned. Rough order, not fixed dates:
- Log your own observations — report what you found on the trail, in a couple of taps, to sharpen the model for everyone.
- Connect Strava & Garmin — link your account so your routes import automatically, no file exporting (today you can already drop a GPX / FIT / TCX file on the map).
- A proper planning tool — build and compare routes by predicted conditions, not just check ones you already have.
- A smarter model — ongoing accuracy improvements as more photos and field reports come in, and finer condition detail beyond dry-vs-moist.
- More of the Alps — extend coverage across the Alpine arc beyond Switzerland.
- Across Europe — scale the engine out to the wider European trail network.
The detailed, technical roadmap — data pipeline, calibration, model training, and the route-import integrations — lives in the project's repository.
Enjoying The Trail Guide?
It's free and independent. A small donation helps cover running costs and keeps it growing.
New here? Read the User Guide to get the most out of the map.