Airfare this year is 200-400 per ticket higher than last year. It doesn't seem to matter when you are traveling. I flew HNL-LAX in June last year, booked 4 weeks in advance and paid $450 per ticket on UA. This year the same route, same dates is $750. Similar stuff for DEN in July.
I've been checking daily and HA fares seem to lower near the end of the week and on the weekends. Not much more than a $20 per ticket drop. UA/AA/DL are usually better midweek. Again, not much of an overall difference. Really, really expensive to fly to/from the islands this year.