Magnetic north

From Glossary of Meteorology

magnetic north

At any point on the earth's surface, the horizontal direction of the earth's magnetic lines of force (direction of a magnetic meridian) toward the north magnetic pole, that is, a direction indicated by the needle of a magnetic compass.

Because of the wide use of the magnetic compass, magnetic north, rather than true north, is the common 0° (or 360°) reference in much of navigational practice, including the designation of airport runway alignment.