Where does this come from, and can I check it?

The gap between the two directions is called declination and varies by location. The figure is taken from USGS, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

Is this really a science fact?

Yes. It sits on the Science shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

What else can I read about it?

The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

Mondo Knows Facts

A compass points to magnetic north, not true north

The gap between the two directions is called declination and varies by location Compass needles align with Earth's magnetic field, whose north pole sits far from the geographic pole. Navigators correct for the difference, which ranges from near zero in some places to more than twenty degrees in others. The magnetic poles also wander measurably from year to year. It sits in Mondo's science collection, one of 200 facts that each trace back to the reference below.

Where this comes from

USGS

Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.

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More facts like this

Birds sense Earth's magnetic field to find their wayA light sensitive protein in the eye may let them see the field There are three different kinds of northTrue north, magnetic north and grid north point in different directions depending on where you stand The magnetic north pole keeps driftingIt has wandered across the Arctic at accelerating speed and now sits well away from the geographic pole Faraday made electricity from a moving magnetA changing magnetic field pushes charges through a coil of wire Earth magnetic poles flip every few hundred thousand yearsGeomagnetic reversals swap the North and South magnetic poles over geologic timescales Permanent magnets lose magnetism when heated above the Curie pointThermal agitation destroys aligned magnetic domains in ferromagnetic materials

Tags: magnetism, navigation, earth

A compass points to magnetic north, not true north: the short answers

Where does this come from, and can I check it?: The gap between the two directions is called declination and varies by location. The figure is taken from USGS, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a science fact?: Yes. It sits on the Science shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.