About
What this is
ShelterCast is a free tool for anyone walking the Appalachian Trail, out for a day, a weekend, a long stretch, or the whole thing. Pick your start and finish crossings and it builds a night-by-night, elevation-adjusted weather outlook for your route, banded across its low and high points each day. No account, no ads, no charge. Weather comes from Open-Meteo; shelter and crossing locations come from NPS/ATC and TopoFusion data. When the National Weather Service has active severe alerts along the trail corridor, a banner at the top of the page summarizes them, with each alert’s headline and affected areas a tap away.
How the forecast works
Multi-day trips aren’t forecast at your exact campsite each night. Pace varies too much between hikers to predict where you’ll be sleeping on night three, so ShelterCast instead samples your whole route at its lowest, middle, and highest elevations and forecasts each of those three points for every day of the trip. The report shows the spread across them: ridges run colder and windier than gaps, and that gap is usually the biggest swing in the weather, bigger than how far along the route you’ve actually walked. Whichever condition is worst across the three points drives that day’s icon and summary, so the report errs toward the rougher end rather than the average. Because that assumption depends on the route staying inside one general climate and weather pattern, trips are capped at 300 miles; a much longer stretch would mix weather from places far outside where you’re actually hiking.
Use your own judgment out there
ShelterCast forecasts are planning estimates, provided as-is with no warranty of accuracy. They are not a substitute for official National Weather Service forecasts, local advisories, or your own judgment in the field. Mountain weather changes fast, and conditions on an exposed ridge can be far worse than any point forecast suggests. Shelter coordinates are approximate: good enough for weather, not for navigation. Outlooks more than 7 days out are historical averages (5-year climatology), not predictions. The severe weather banner, when shown, reflects active National Weather Service alerts along the trail corridor; it can lag or be briefly unavailable, so never treat its absence as an all-clear. Check current conditions before you go, carry gear for worse weather than forecast, and make your own calls on the trail.
Privacy
There are no accounts, no sign-up, no ads, and no tracking cookies. To keep the tool free for everyone, we hold your IP address in a counter for up to 24 hours to limit each visitor’s daily forecasts; it expires on its own and is not used for anything else. We use cookieless, first-party page analytics (aggregate visit counts, no cross-site tracking) and keep an aggregate tally of forecasts served. To learn which parts of the trail people plan for, we also keep a log of what was searched: the shelters or crossings, dates, and trip length of each forecast request we can answer, plus whether we could serve it. It records what was asked, never who asked; no IP address or other identifier is stored with it. Forecast and alert requests go to Open-Meteo and the National Weather Service from our servers, so your browser never talks to a third party. Our hosting providers (Vercel, Cloudflare) keep standard server logs. Questions? feedback@sheltercast.org