Cloud ceiling
≥ 1,500 ft AGL. The base of the lowest BKN or OVC layer (or vertical visibility into an obscured sky) must exceed 1,500 feet above aerodrome level.
Annual VMC/IMC statistics for any ICAO airport — data-driven VFR planning powered by the Iowa Environmental Mesonet, with live METAR/TAF from aviationweather.gov.
Criteria
Visual Meteorological Conditions (VMC) allow operations under Visual Flight Rules (VFR). For a day to be classified as VMC, at least 75% of its METAR observations must simultaneously satisfy all of the following, per Class E airspace below 10,000 ft.
≥ 1,500 ft AGL. The base of the lowest BKN or OVC layer (or vertical visibility into an obscured sky) must exceed 1,500 feet above aerodrome level.
≥ 5 km (3 SM) below 10,000 ft. The prevailing meteorological visibility reported in the METAR must be at least 5 kilometres to allow visual navigation.
≥ 1,500 m from clouds. The aircraft must keep a minimum horizontal distance of 1,500 metres from any cloud to avoid inadvertent IMC entry.
≥ 1,000 ft from clouds. Both above and below, the aircraft must remain at least 1,000 feet clear of any cloud in the vertical plane.