Editing Visual meteorological conditions (section)

{{Short description|Flight category allowing pilots to fly using vision as well as instruments}}
 [[File:US airspace visibility 2016.jpg|thumb|VFR / VMC visibility requirements in the US]]
In [[aviation]], '''visual meteorological conditions''' ('''VMC''') is an [[aviation flight category]] in which [[visual flight rules]] (VFR) flight is permitted—that is, conditions in which [[aviator|pilots]] have sufficient visibility to fly the [[aircraft]] maintaining visual separation from terrain and other aircraft. They are the opposite of [[instrument meteorological conditions]] (IMC). The boundary criteria between IMC and VMC are known as the VMC minima and are defined by: [[visibility]], cloud ceilings (for [[takeoff]]s and [[landings]]), and cloud clearances.

The exact requirements vary by type of [[airspace]], whether it is day or night (for countries that permit night VFR), and from country to country. Typical visibility requirements vary from one statute mile to five statute miles (many countries define these in metric units as 1,500 m to 8&nbsp;km). Typical cloud clearance requirements vary from merely remaining clear of clouds to remaining at least one mile away (1,500 m in some countries) from clouds horizontally and 1,000 feet away from clouds vertically. For instance, in Australia, VMC minima outside controlled airspace are clear of cloud with 5,000 m visibility below 3,000&nbsp;ft [[AMSL]] or 1,000&nbsp;ft [[Above ground level|AGL]] (whichever is higher), and 1,000&nbsp;ft vertical/1,500 m horizontal separation from cloud above these altitudes or in controlled airspace. Above 10,000&nbsp;ft, 8,000 m visibility is required to maintain VMC. Air traffic control may also issue a "special VFR" clearance to VFR aircraft, to allow departure from a control zone in less than VMC – this reduces the visibility minimum to 1,600 m.

Generally, VMC requires greater visibility and cloud clearance in [[controlled airspace]] than in [[uncontrolled airspace]]. In uncontrolled airspace there is less risk of a VFR aircraft colliding with an [[instrument flight rules]] (IFR) aircraft emerging from a cloud, so aircraft are permitted to fly closer to clouds. An exception to this rule is [[airspace class|class B airspace]], in which [[Air traffic control|ATC]] separates VFR traffic from all other traffic (VFR or IFR), which is why in class B airspace lower cloud clearance is permitted.