What defines Instrument Meteorological Conditions (IMC)?

Instrument Meteorological Conditions (IMC) refer specifically to the weather conditions in which pilots must rely on instruments for navigation rather than visual references outside the cockpit. This situation typically occurs when the weather is such that visibility is severely restricted, such as in fog, heavy precipitation, or low clouds, making it unsafe or impossible to see landmarks or the horizon. Under IMC, pilots need to reference cockpit instruments to maintain control of the aircraft and navigate safely.

In contrast, the other options describe conditions that are not consistent with IMC. Some suggest favorable weather for visual flight (visual flight rules), which is not applicable in IMC scenarios. Others imply an ability to use visual cues for navigation, which contradicts the very definition of IMC. Additionally, stating that IMC always involves severe weather is misleading, as IMC can occur under various conditions, not exclusively severe ones.