In short
See Arrow colours and wind direction.
This topic is now part of the combined guide.
Why do your arrows point the wrong way?
More Weather Help
What is the Beaufort Scale?
What's the difference between Swell, Waves & Seas?
How to read the Wind graphs
What is the difference between waves and swell?
How to read wind forecasts
How does the weather work?
How do "My Graphs" / My Weather layouts work?
Slow, Jittery or Lagging drawing of the weather graphs