The Dublin sale has spread across the country to Los Angeles today with American/Oneworld, Delta/SkyTeam and United/Air Canada/Star Alliance. There are Air Canada tickets under $400 round trip available through a Momondo.com OTA search on some dates. The airlines themselves are offering fares at about $502 to $550 round trip for departures as soon as next week and all the way into May 2017, except American only has fares in $500s September and October, and rising to $600s after first week of November.
Fares are about $20 lower from Los Angeles than San Francisco.
Air Canada Los Angeles LAX – Toronto YYZ – Dublin, Ireland DUB – Vancouver YVR – Los Angeles LAX
American Airlines San Francisco SFO – Philadelphia PHL – Dublin DUB – PHL – SFO
The latest date I see on the airline’s websites for travel on these low fares is May 10. Low fares are available with both United/Star Alliance and Delta/SkyTeam Alliance airlines.
Delta Airlines San Francisco SFO – New York JFK – Dublin DUB – New York JFK – San Francisco
These same Delta flights are available for $539.05 on Air France website.
Or back to Momondo.com meta-search shows ExploreTrip.com has Air Canada flights on these same dates May 10-18 for $427.63 round trip.