Plain English Meaning

The magnetic north reference baked into a VOR station when it was last calibrated. Because Earth's magnetic north slowly moves, that baked-in reference may no longer match today's actual magnetic variation in the area.

Full Definition

The angular difference between true north and the magnetic north reference used to align a VOR station's radials at the time the station was last calibrated. Because magnetic north drifts over time, station declination can differ from the current local magnetic variation, causing small bearing discrepancies between a VOR's published radials and what a pilot would expect from charted variation alone.

Context Anchor

Seen in and discussions when comparing true north, magnetic north, and the way a VOR or similar station is aligned.