Definition
In a METAR, SCT is the sky cover contraction reporting that clouds cover three-eighths to four-eighths (3/8 to 4/8) of the sky at a given layer, measured in oktas. It is reported with a height in hundreds of feet above the station, for example SCT040 meaning a scattered layer at 4,000 feet AGL.
Plain English
SCT means the sky at that height is between roughly one-third and one-half covered with clouds — more than just a few, but well short of mostly cloudy.
Context Anchor
Seen in the sky condition section of a METAR, such as SCT025 or SCT080.
Derivation
SCT is a shortened form of 'scattered.' The word comes from the Middle English 'scateren,' meaning to throw loosely about. That image fits the meaning here — clouds spread loosely across the sky rather than clumped together or covering it.
Why Pilots Care
Helps pilots quickly judge sky conditions that affect visibility and VFR flight options.
Intuition Check
Do not read “scattered” as a vague everyday word here. In a METAR, SCT has a specific amount: 3/8 through 4/8 of the sky covered by clouds.
Example Sentence 1
The METAR reported SCT040, so we briefed for a scattered cloud layer around 4,000 feet on departure.
Example Sentence 2
With SCT coverage we could still see the ground between the clouds.