What Does VV Mean in a METAR?
VV means vertical visibility: how far you can see upward into an obscuration such as fog or heavy snow. There is no cloud base, and the VV height acts as an indefinite ceiling. It stands for VV = Vertical Visibility.
VV in a real report
1/4SM FG VV002
That reads as quarter mile in fog, vertical visibility 200 ft.
What it changes for you
VV and a cloud layer at the same height are not the same approach.
Under a broken or overcast layer there is clear air below the base, and you break out into it. Under an obscuration there is no base to break out of. The obscuring medium continues to the ground, and forward visibility on the runway is whatever the surface visibility group says.
VV/// means the vertical visibility could not be measured at all. Treat that as
worse than a number, not as missing data.
What causes it
Fog most often, then heavy snow, blowing dust and smoke. The body of the report tells you which, and that matters because fog can lift in an hour while smoke may not.
Related codes
Decode a report containing this code
Paste a METAR, TAF, PIREP or SIGMET into the WxDecoder decoder. Every group comes back in plain English. The raw code sits beside it, so you can check the decode rather than trust it.
Frequently asked questions
What does VV mean in a METAR?
Vertical visibility into an obscuration. VV002 means you can see 200 feet upward into fog, heavy snow or another obscuration. There is no cloud base, because the sky is hidden rather than covered by a layer.
Does VV count as a ceiling?
Yes. Vertical visibility is treated as a ceiling for the flight category, so VV002 gives a 200 foot ceiling. It is often worse to fly than a cloud layer at the same height, because there is no clear air underneath.