natural event vs occurrence

natural event and occurrence both are nouns.

Word	Noun	Adjective	Verb	Adverb
natural event	Yes	No	No	No
occurrence	Yes	No	No	No

As nouns, natural event and occurrence are synonyms defined as:

Other synonyms of natural event include happening, occurrent.

natural event (noun)	occurrence (noun)
an event that happens	an event that happens
	an instance of something occurring