Translation guide
A device that shows wind direction, often found on rooftops.
A device, often decorative, that rotates to show the direction of the wind.
The most common and natural term for a weather vane, especially the decorative rooster-shaped ones. Literally 'wind-viewing chicken'.
屋根の上に風見鶏がある。
There is a weather vane on the roof.
A more technical or generic term for a wind direction indicator, not necessarily decorative. Used in meteorological contexts.
A shorter, less common term for a weather vane. May be understood but not as widely used as 風見鶏.
空港には風向計が設置されている。
A wind direction indicator is installed at the airport.
The old weather vane is turning in the wind.