There are descriptions of Árstíðir being "indie" and "folk." These are not wrong.
When listening to Árstíðir, I'm reminded of Kansas, a rock group from the 1970s. Tell me "Ljóð í sand" doesn't remind you of "Dust in the Wind," for starters. "Á meðan jörðin sefur" also has strong Kansas similarities.
They provide enjoyable listening. I don't understand Icelandic, yet feelings come through.