Sunday River

Each location is refreshed once every three hours. The 7-day forecast, luck factor and packing notes are computed from the same stored update.

A score comparing how good mtb is likely to be this week at Sunday River with the version-matched historical observations available for this time of year.

Open-Meteo, a free open weather API that blends multiple national weather services plus an archive going back decades. The same data powers many outdoor apps.

It means the weather data suggests good conditions. Local factors like lift closures, off-piste avalanche risk and grooming still matter. Check resort webcams and the local piste report before committing.

Check our timing score heatmap on the Season tab for a week-by-week breakdown combining snow conditions with school holiday crowd pressure.