What is the meaning of MVFR, as used in aviation weather terminology?

MVFR stands for "Marginal Visual Flight Rules." This classification is used in aviation to denote weather conditions that are not ideal for visual flight but are still somewhat acceptable for VFR operations. Specifically, MVFR is defined as a ceiling between 1,000 and 3,000 feet above ground level and/or visibility between 3 and 5 miles.

In this context, the significance of these thresholds is that they provide guidelines for pilots regarding the conditions under which they can operate their aircraft visually. Understanding MVFR helps pilots assess whether external conditions might necessitate a switch to instrument flight rules (IFR), ensuring safety during flight operations.

The other options describe weather conditions that either fall outside the marginal range or signify less acceptable flying conditions, such as those categorized under VFR (generally favorable) or IFR (less favorable).