Declination

Declination is the angular difference between magnetic north (where a compass needle points) and true north (the actual direction to the North Pole) at any given location on Earth. This difference varies by geographic location and changes slowly over time, requiring hikers and backpackers to adjust their compass readings when using topographic maps for navigation. Most topographic maps include the local declination value, which outdoor enthusiasts must account for to ensure accurate navigation and route-finding in the backcountry.