Why Do Pilots Say 'Winds Aloft Are True' When Forecasts Are Often Inaccurate?

It’s important to remember that true north and magnetic north are not the same.

Meg Godlewski

Wednesday, March 19, 2025 at 10:45 AM ET

Verified

Edited By:

Kimberly Johnson

The difference between true and magnetic north measured in degrees is called variation. [Credit: Shutterstock]

Key Takeaways:

The phrase "winds aloft are true" signifies that the wind direction is referenced to true north (the Earth's geographic axis), not magnetic north.
The difference between true north and magnetic north is called "variation," which is location-dependent and depicted on VFR sectionals.
Winds aloft are forecasts, meaning they are predictions derived from data analysis, and are therefore inherently subject to inaccuracies compared to actual conditions at altitude.

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Question: Why do people say, “Winds aloft are true,” when what is forecast is often notoriously inaccurate from what you really experience at altitude? I am a student pilot and this has messed me up several times.

Answer: In this case the word “true” means in reference to “true north” as opposed to magnetic north.

True north, per Chapter 8 of the Pilot’s Handbook of Aeronautical Knowledge (PHAK), is the geographic axis that the Earth rotates about. Think of how a globe is mounted with the posts at the physical north and south poles.