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Magnetic Declination

Magnetic declination Washington, DC Declination (degrees west) at Washington, DC 1750 - 2005

Magnetic declination, sometimes called magnetic variation, is the angle between magnetic north and true north. Declination is considered positive east of true north and negative when west.

As illustrated in the graph to the left, magnetic declination changes over time and with location.

If you would like to learn more about magnetic declination and Earth's changing magnetic field, we recommend visiting NGDC's Answers to Frequently Asked Questions.

A declination map for the continental US (2010). Click for higher resolution version.
Declination map for the US Declination Map from GIS map viewer