Event insurance will not cover material damages caused by rain at an outdoor event. As this is the hosts responsibility to make sure no equipment is critically damaged by the rain when outdoors.
Event Insurance will not cover pandemic cancelations. Over time the world wide pandemic showed insurance company that there is an increasing chance of events being cancelled by Covid.
Before a you plan your event, It is best to consult with specialist insurance providers who understand your event and can help you pick the right kind of event insurance policy that fits your events risk.
It is best to buy event insurance in advance, at-least two weeks before the event , incase of the weather and sudden unpredictable situations.