Plain English Meaning

The lowest visibility and cloud-clearance limits the rules allow before you can no longer fly by looking outside. If conditions drop below these numbers, you can't legally fly VFR.

Full Definition

The minimum weather conditions — specifically flight visibility and distance from clouds — that a pilot must have in order to legally operate an aircraft under Visual Flight Rules. The exact values depend on airspace class, altitude, and time of day, and are set by regulation (14 CFR 91.155).

Context Anchor

You encounter this term when checking weather before a flight, especially before a night flight, and when deciding whether conditions are enough to fly by .