SkyTeam airlines Delta/KLM/Air France have San Francisco to Copenhagen, Denmark for $429 round trip for travel departures from April to early June 2018.
Oslo, Bergen, Trondheim, Kristiansand and Stavanger are around $480 round trip. Stockholm and Gothenburg, Sweden under $500.
$430 Delta SFO – CPH Copenhagen, Denmark
$478 SkyTeam Air France SFO – OSL Oslo, Norway
$478 SkyTeam Air France SFO – Bergen, Norway
$481 SkyTeam SFO – Kristiansand, Norway KRS
$481 SkyTeam SFO – Stavanger, Norway SVG
$481 SkyTeam SFO – Trondheim, Norway TRD
Similar fares are available to Oslo and a few other cities with Star Alliance airlines Lufthansa and Swiss too.
$446 Star Alliance SFO – Oslo, Norway OSL
Delta Airlines San Francisco SFO – New York JFK – Copenhagen CPH – JFK – SFO
$429.11 round trip Mon May 28 – Wed Jun 6
