BivioSeason and snow
Up high, the season doesn't follow the calendar down in the valley. Here's how to read snow, frost and lift dates before you pick your day.
For each hike, one sentence tells you whether it climbs above the freezing level forecast that day (the lowest between 8 am and 6 pm): above it, frost and ice are possible. Next to it, its profile from start to finish, blue where it climbs above 0 °C, and the snow measured that morning at the station closest in altitude.
Reading the forecast and the stations…
A station measures snow at its own altitude, not along your whole trail. On the spot, snow on a given stretch is something you see on the ground.
Hiking trails are only maintained when they're free of snow and ice. The rest of the year, it's up to you to check their condition, especially in spring and autumn.
In the mountains, trails clear much later than in the lowlands. And from autumn on, the first snow can come back up high.
Snow can linger up high, often old, hard-packed snow. Go around steep snow slopes. Slipping on a snowfield can be fatal: without the right gear and experience, take another route or turn back.
In the morning, the ground can still be frozen. In spring, avalanches sometimes start far above and run down onto snow-free ground.
Before you go, ask the tourist office or the lift company whether the mountain trails are passable yet, and check the local webcams.
Days get shorter: plan to be back before dark. Some trails can be icy even with no snow; if so, turn back.
It's hunting season too: find out about hunting areas and wear bright clothes. Some huts and lifts close at the end of the season.
Bivio never tells you a trail is dry or open. It shows you what's been measured and forecast, with the source and the time we read it, so you can decide.
The MeteoSwiss local forecast, day by day and hour by hour along your day out.
Snow measured each morning at MeteoSwiss stations and SLF automatic stations near the trail, with their altitude.
The freezing level (0 °C line) forecast by MeteoSwiss.
An alert when frost is forecast at the top of the trail, or when the 0 °C line drops below its highest point: snow and ice are then possible up there.
A station measures snow at its own altitude, not along your whole route. If your hike climbs higher than the highest nearby station, Bivio tells you: up there, nobody's measuring. Most manual measuring sites are below roughly 2,000 m.
An empty box means "no measurement", never zero centimetres.
Many hikes start or finish with a cable car, a mountain railway or a bus that only runs part of the year. The region pages list their dates under "When to go": Valais, Bernese Oberland, Vaud Alps.
For the way back, always check the time of the last run.
Bivio's hikes follow SwitzerlandMobility's summer routes. In winter, you walk on other trails.
Winter hiking trails are marked in pink, with a hiker symbol. They're prepared, and technically similar to yellow summer trails.
Snowshoe trails are pink too, with a white snowshoe symbol. They're not tracked and often run away from prepared paths; their difficulty is shown in blue, red or black. You need snowshoes, poles, sure footing and an understanding of avalanche danger: the SLF avalanche bulletin comes out once or twice a day in winter.
Allow more time: cold and snow slow you down, and days are short.
It depends on the year's snow and the altitude. Ask the tourist office or the lift company, and check the measured snow on the hike page.
Only when they're free of snow and ice. In spring, autumn and winter, it's up to you to judge their condition before you go.
It's the altitude where the air is at 0 °C, forecast hour by hour by MeteoSwiss. If it drops below your hike's highest point, Bivio warns you: snow and ice are possible up there.
Pink. A hiker symbol for winter hiking trails, a white snowshoe for snowshoe trails.
It depends on each lift. The region pages give season dates under "When to go", and the operator publishes its timetable.
Bob relies on the site's data (SwitzerlandMobility, MeteoSwiss, official timetable) and can be wrong. On the ground, the signposts come first. Emergency: 1414 (Rega) or 112.