Lapse rate can be used to describe several atmospheric variables, but for hikers lapse rate is generally observed as the tendency for temperature to predictably fall with altitude. In general, backpackers and hikers can expect a temperature decrease / lapse rate of several degrees Fahrenheit for every 1000 feet of elevation gain. Lapse rate occurs in concert with and due to the lower air pressure found at altitude. When planning a mountain trip, lapse rate is important to consider so that you can adequately prepare for anticipated temperatures at altitude – instead of the forecast for the closest town that may be thousands of feet lower than where you’ll be hiking (although point forecasts from the National Weather Service can be helpful here).

On trips that feature plenty of elevation change, knowing the effects that lapse rate can have on temperature can help when it comes to deciding on a route and / or place to camp.

Lapse Rate Backpacking & Hiking Application

Lapse rate can be worth consideration while actually on a trip as well when it comes to choosing a location to camp for the night or decisions between two trails or routes. I personally am typically keeping an eye on altitude in the mountains, and subsequently can anticipate lapse rates all on the fly using a solar powered ABC watch. Generally, camping lower will result in a warmer night and by taking a lower trail, or camping lower, one can often choose their own weather during storm systems and hike and camp in rain vs. snow for example. However, there are exceptions to the rule when it comes to lapse rate – within the same general elevation, a bench above the valley floor will be warmer at night than the bottom of the valley where cold air will settle. Additionally, an inversion situation can throw a wrench into normal lapse rates.

Editor's Note: This article originally appeared in Issue 50 of TrailGroove Magazine. You can read the original article here.