Chapter 11 · Forest and mountains
Mountain weather
- It gets colder as you climb. On average, the temperature drops about 3.5 °F for every 1,000 ft of altitude (6.5 °C per kilometer). If it is 70 °F (21 °C) at the base, at 4,000 ft higher it can be 56 °F (13 °C), before adding wind.
- Summer storms build in the afternoon. Start early and plan to be off the high ground before noon.
- Wind chills you much more than temperature alone (see wind chill in chapter 14). Always carry a wind and rain layer.
- What starts as rain can end in hypothermia, even at temperatures of 50 °F (10 °C). Wet clothing + wind + fatigue is the classic combination (chapter 14).
- Valleys and canyons funnel water. A storm you cannot see, upstream, can send a flood down to you under clear skies.
- Fog and low clouds erase landmarks in minutes. If you cannot see, stop and wait (chapter 8).
