The more severe the magnitude of the event or the intensity of impact, the higher the hazard. The various disaster event scales clarify that relationship – if your island nation has a history of being struck by Super Typhoons, you have a different problem than if your historic worst oceanic storm is a tropical disturbance.

Events which can occur at any time of day throughout the year pose a different hazard than those that are seasonal or that commonly occur during only part of the day.  The individual event in a restricted season may be of catastrophic intensity.  For example, the Super Typhoon is a greater national hazard than a crash of a passenger aircraft.  However, you must maintain readiness to deal with the worst case aircraft crash impact throughout the year.

The longer the event duration the greater the hazard.  Consider the both the impact and recovery periods, which may be prolonged for weeks, months, or years.  A major earthquake happens in seconds, but the combined response and recovery effort may take years.

The shorter the timeline for development of the event the higher the hazard.  In the earthquake example, absent foreshocks to trigger increased readiness, the time does not allow pre-impact response actions to preserve life and property.  On the other hand, given good weather forecasting, a developing winter storm may provide hours or days of warning.