How much colder is it at elevation on the Appalachian Trail?
Figure roughly 3.5°F colder for every 1,000 feet you climb. The Appalachian Trail runs from about 124 feet above sea level, where it passes the Hudson River in New York, to 6,643 feet at Clingmans Dome in the Great Smoky Mountains, so elevation alone can swing trail temperatures by more than 20°F before the weather itself even enters the picture. That gap is why a forecast pulled for the nearest town so often reads nothing like the night you actually spend on a ridge.
How much does elevation vary along the Appalachian Trail?
More than 6,500 feet end to end, and often several thousand feet within a single day’s walk. The highest shelter on the trail, Roan High Knob Shelter in Tennessee, sits at 6,198 feet; the lowest, Ten Mile River Shelter in Connecticut, sits near 340 feet. In the Smokies, a hiker leaving Davenport Gap (about 2,000 feet) for Icewater Spring Shelter (5,938 feet) climbs through roughly 4,000 feet of elevation, which by lapse rate alone is a shift of about 14°F, comparable to hiking several hundred miles north without changing altitude.
| Shelter | Elevation | State |
|---|---|---|
| Roan High Knob Shelter | 6,198 ft | TN |
| Tri-Corner Knob Shelter | 5,951 ft | NC |
| Icewater Spring Shelter | 5,938 ft | NC |
| Mount Collins Shelter | 5,869 ft | TN |
| Double Spring Gap Shelter | 5,528 ft | TN |
What is the temperature lapse rate?
The lapse rate is how fast air cools as it rises: on average about 3.5°F per 1,000 feet of elevation (6.5°C per kilometer). It is not fixed. In humid, cloudy weather the drop can be closer to 3°F per 1,000 feet, while in dry, clear air it can exceed 5°F. And on calm, clear nights the pattern can briefly invert: cold air drains into gaps and hollows, leaving a ridge a few degrees milder than the valley below until the sun or wind stirs the layers back up. Over a multi-day trip, though, the rule of thumb holds: higher is colder, and the difference is large enough to change what you pack.
Why does the town forecast mislead AT hikers?
Because weather apps default to the nearest town, and trail towns sit in valleys. Newfound Gap, where the trail crosses US 441 in the Smokies, is at 5,115 feet, close to 4,000 feet above the towns on either side of the park; the shelters on the ridgeline above it are higher still. A town forecast of 60° with a 45° overnight low can mean a ridge that never leaves the 40s by day and drops below freezing at night. The forecast was not wrong. It was answering a question about a place 4,000 feet below where you are sleeping.
How does wind change what you feel?
Wind is the second half of the elevation penalty. Ridgelines and balds are exposed in a way valleys never are, and wind chill compounds the lapse rate: a 30°F night in a 20 mph ridge wind feels like about 17°F on skin and strips heat from a shelter or tent far faster than the still-air temperature suggests. This is why an elevation-aware forecast reports wind alongside temperature, and why the rougher end of a forecast range is the one worth packing for.
How do I get an elevation-adjusted forecast for my hike?
ShelterCast builds one for free: pick your start and finish crossings and it forecasts your route at its lowest, middle, and highest elevations for every day of the trip, or pick a single shelter for a 10-day outlook at that shelter’s own elevation. Each request asks the weather model for conditions at trail altitude rather than the nearest valley station. More detail on how it works is in the FAQ.