Clouds at 1,200 ft obscure 2/8 of the sky (FEW). Higher clouds at 3,000 ft obscure an additional 1/8 of the sky, and because the observer cannot see above the 1,200-ft layer, they are to assume that the higher 3,000-ft layer also exists above the lower layer (SCT). The highest clouds at 5,000 ft obscure 2/8 of the sky, and, again, since the observer cannot see past the 1,200 and 3,000-ft layers, they are to assume the higher 5,000-ft layer also exists above the lower layers (BKN). The sky condition group would be coded as: FEW012 SCT030 BKN050.

At manual stations, cumulonimbus (CB) or towering cumulus (TCU) is appended to the associated layer. For example, a scattered layer of towering cumulus at 1,500 ft would be coded SCT015TCU and would be followed by a space if there were additional higher layers to code.

Examples:

SKC No layers are present.

CLR No layers are detected at or below 12,000 ft AGL.

FEW004 Few at 400 ft AGL.

SCT023TCU Scattered layer of towering cumulus at 2,300 ft AGL.

BKN100 Broken layer (ceiling) at 10,000 ft AGL.

OVC250 Overcast layer (ceiling) at 25,000 ft AGL.

VV001 Indefinite ceiling with a vertical visibility of 100 ft AGL.

FEW012 SCT046 Few clouds at 1,200 ft, scattered layer at 4,600 ft AGL.

SCT033 BKN085 Scattered layer at 3,300 ft, broken layer (ceiling) at 8,500 ft AGL.

SCT018 OVC032CB Scattered layer at 1,800 ft AGL, overcast layer (ceiling) of cumulonimbus at 3,200 ft AGL.

SCT009 SCT024 BKN048 Scattered layer at 900 ft AGL, scattered layer at 2,400 ft AGL, broken layer (ceiling) at 4,800 ft AGL.

Temperature is the degree of hotness or coldness of the ambient air, as measured by a suitable instrument. Dewpoint is the temperature to which a given parcel of air must be cooled at constant pressure and constant water vapor content for the air to become fully saturated.

Temperature and dewpoint are coded as two digits rounded to the nearest whole degree Celsius. For example, a temperature of 0.3°C would be coded at 00. Sub-zero temperatures and dewpoints are prefixed with an M. For example, a temperature of 4°C with a dewpoint of -2°C would be coded as 04/M02; a temperature of -2°C would be coded as M02.

If temperature is not available, the entire temperature/dewpoint group is not coded. If dewpoint is not available, temperature is coded followed by a solidus (/) and no entry is made for dewpoint. For example, a temperature of 1.5°C and a missing dewpoint would be coded as 02/.