Where is magnetic declination the worst geographically?

It is always a given that the compass points towards the magnetic north and not the true north. The magnetic declination is the angle between the magnetic north and the geographic north. It varies from time to time due to the constantly shifting magnetic field.

Geographically, the "magnetic declination" is the worst in the northeastern part of the United States.

Explanation:

According to the map that shows the plot of the magnetic declination of the world, the worst magnetic declination is seen in the northeastern part of the USA. The magnetic declination here, specifically in the state of Washington, is close to 21°.In this part of the United States, the explorers and travelers need to adjust the magnetic compass up to 21° to get the true north.