How can I find a Obituary, In Honolulu, Hawaii, for August 1989?

Answer 1

You'll have to go to the library for that and go thru tons of microfilms for that month and year.

Answer 2

Sometimes the local newspapers will retain copies, as well. If you aren't local in Hawaii, and don't know anybody who is, you may do well to make a few calls and see if they have any records on microfilm or digital.

Otherwise, I agree the library is your best source for an older obituary.