How to read a wind barb
A wind barb shows direction and speed in one small symbol — the way sailors and forecasters read the wind. Once you can read it, it's faster than any words.
The speed
Count the feathers on the staff and add them up: a short feather is 5 knots, a long feather is 10, and a solid flag is 50. A bare ring means calm. So a barb with two long feathers and a short one is 25 knots.
The direction
The staff points into the wind — the direction the wind is blowing from. The barb above points to the south-west, so it's a south-westerly. On the maps the whole barb sits at the station and turns as the wind shifts.
Which side are the feathers?
The feathers stay on one fixed side of the staff — the left, here in the Northern Hemisphere (down in the south they'd be on the right). The whole symbol turns with the wind, so as it swings from a northerly to a southerly the feathers stay on the same side of the staff — they just come around with it.
On the maps
Each barb is also coloured by strength — grey when it's calm, greens for a good sailing breeze, then amber, orange and red as it builds — and the exact speed is written beside it. Read it at a glance by colour, or feather-by-feather when you want the detail.