Wind Strength: light

Strength Values Effect on Land Effect on Ocean
Still 0-19 km/h Wind felt on face; leaves rustle; Sea like a mirror with small wavelets forming but not breaking, a glassy appearance is maintained.
Light 20-29 km/h Raises dust and loose paper; small branches are moved. Small waves - becoming longer; fairly frequent white horses.
Medium 30-39 km/h Small trees in leaf begin to sway; crested wavelets form on inland waters Moderate waves, taking a more pronounced long form; many white horses are formed - a chance of some spray
Strong 40-49 km/h Large branches in motion; whistling heard in telephone wires; umbrellas used with difficulty. Large waves begin to form; the white foam crests are more extensive with probably some spray
X-Strong 50 km/h + Whole trees in motion; inconvenience felt when walking against wind. Sea heaps up and white foam from breaking waves begins to be blown in streaks along direction of wind.