The correct answer is - Dublin is warmed by ocean currents.
Dublin is warmed by ocean currents, more specifically the Golf Ocean Current which is a warm and wet ocean current, so it makes the climate in Ireland, and also Britain, and Norway much warmer than it is supposed to be according to their respective latitudes. On the other hand, San Francisco is influenced by cold sea currents that come both from the north and the south and make it's temperature lower than what is expected at this latitude.