Alaska Airlines has a good sale for Hawaii happening for Oakland OAK and San Jose SJC to Honolulu HNL and Maui OGG. While $98 one way is not as cheap as Southwest Airlines $98 round trip, there are probably more dates available after many of the low deals on Southwest have already sold out for spring travel.
Departure dates are available with no advance for flights as soon as March 5. I see fares as late as June 19 for $98.60 one way for SJC-OGG. $98 one way fares return for travel August and September.
Alaska Airlines San Jose SJC – Kahului/Maui OGG
Economy X fare has restrictions.
Upgrading to Economy R fare for $40 round trip allows free seat selection at time booking.
Both R and X fare classes earn 100% flight miles.
Easiest way I find to construct a low cost fare is search one way flights on Google Flights.