| What it is | Loss of contrast in snow/flat light |
| Effect | No horizon, ground, or slope sense |
| Navigate by | Map, compass, GPS |
| Difficulty | Intermediate (hazard) |
A whiteout is a weather condition in which falling or blowing snow and flat light erase all visual contrast, so the ground, horizon, and sky blend into uniform white. Hikers and mountaineers can lose all sense of direction and slope, making navigation by map, compass, and GPS essential and travel hazardous.
The danger
With no reference, parties wander off route or over cornices and cliffs — a serious objective hazard, often with cold and wind.
Navigating it
Use a map, compass bearings, and GPS — or stop and wait it out. Educational only; not a substitute for instruction.
Frequently asked questions
What is a whiteout?
A whiteout is a condition — from heavy snow, blowing snow, fog, or flat light off snow — in which everything looks uniformly white and you lose all visual reference. You can't see the horizon, judge the slope angle, or even tell up from down on snow, which is profoundly disorienting.
How do you navigate in a whiteout?
By instruments, not sight: a map and compass (taking and following precise bearings), a GPS or altimeter, and careful pacing to track distance. Techniques include sending a teammate ahead as a visual reference and using slope aspect. Often the safest choice is to stop and wait it out.
Are whiteouts dangerous?
Yes — they cause climbers and skiers to wander off route, walk over cornices or cliffs, or fail to find shelter, and they often accompany cold and wind that raise hypothermia risk. Many mountain accidents involve whiteouts, which is why early starts and navigation skills matter.
Sources
- Whiteout navigation — The Mountaineers