Introduction & principle
u=−S sin Φ and v=−S cos Φ; speed=√(u²+v²). Direction uses atan2(−u,−v), normalized to 0–360°. Meteorological direction is where wind comes from. Calm direction is undefined.
All tools
Meteorological Calculation
Wind Direction & Vector Components
Convert wind-from speed/direction to eastward/northward components and back.
Use this tool
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Worked example
10 m/s from 270° gives u=+10 m/s and v≈0. Components u=0, v=−10 correspond to a northerly wind, 0°.
Detailed usage guide
- 1Choose speed/direction or u/v component input.
- 2Enter values in m/s; direction is clockwise from true north and indicates wind from.
- 3Read the complementary representation. Zero speed has no direction.
Common problems & FAQ
Which wind-direction convention is used?
Wind-from degrees clockwise from true north. A westerly wind comes from 270° but moves eastward, so u is positive. Calm wind has no defined direction.
Methods & references
Method reviewed November 4, 2026. These tools support learning and recording, not safety-critical decisions.