Cloud Cover: FEW, SCT, BKN and OVC in a METAR

A METAR reports cloud in oktas, which are eighths of the sky. The height of the cloud base follows. Together they form groups such as SCT018.

The four amounts

• FEW (few) stands for 1 to 2 oktas.
• SCT (scattered) stands for 3 to 4 oktas.
• BKN (broken) stands for 5 to 7 oktas.
• OVC (overcast) stands for 8 oktas.

According to the FAA handbook, with OVC the whole sky is covered.

The cloud base

Three digits follow the code. They give the height of the cloud base in units of 100 ft. So SCT018 means 3 to 4 oktas with the cloud base at 1,800 ft.

Up to 10,000 ft a METAR reports the base in steps of 100 ft, above that in steps of 1,000 ft. Observed values are rounded down to the next lower step. The height is measured above aerodrome elevation, not above mean sea level. Only for reports from offshore structures does mean sea level apply.

Several layers and cloud types

A METAR can contain several cloud groups, normally no more than three. They appear in ascending order of height above ground level. The reported layers are the lowest layer of any amount, the next layer if it covers more than 2 eighths, the next higher layer if it covers more than 4 eighths, and cumulonimbus (CB) or towering cumulus (TCU) if they are not already in one of the groups.

A real example from the station LOWW on 22 October 2026 at 06:20 UTC: FEW032 SCT038 BKN044. These are three layers, with bases at 3,200 ft, 3,800 ft and 4,400 ft above aerodrome elevation. Source: aviationweather.gov, retrieved on 22 October 2026.

Of all cloud types, a METAR reports only CB and TCU, as a suffix after the height, for example FEW010CB. TCU stands for towering cumulus, the ICAO term for cumulus congestus.

When cloud forms a ceiling

The ceiling is the height above the ground or water of the base of the lowest layer of cloud below 6,000 m (20,000 ft) that covers more than half the sky. More than half means 5 oktas or more, so BKN or OVC. FEW and SCT do not form a ceiling.

SERA uses the ceiling as a minimum value: unless you have an air traffic control clearance, you must not take off or land as a VFR pilot at an aerodrome within a control zone, or enter the aerodrome traffic zone or traffic circuit, when the reported conditions at the aerodrome are below the minima. The minima are a ceiling below 450 m (1,500 ft) or a ground visibility below 5 km.

Special cases

• CAVOK replaces visibility, weather and cloud when visibility is 10 km or more, there is no cloud of operational significance and there is no significant weather. A cloud of operational significance has its base below 1,500 m (5,000 ft) or below the highest minimum sector altitude, whichever is greater, or is a cumulonimbus or towering cumulus at any height.
• NSC (Nil Significant Cloud) is used when there is no cloud of operational significance, vertical visibility is not restricted and CAVOK is not appropriate.
• NCD is reported by an automatic system when it detects no cloud.
• VV003 replaces the cloud group when the sky is obscured and the vertical visibility is known, here 300 ft.

What the EASA syllabus says

In the PPL(A) theoretical knowledge syllabus, “Aviation weather messages” belong to Meteorology, under “Information for flight planning”.