I am investigating the feasibility of a hike looping around Hofsjökull. This will take me through several “deserts” such as Hofsafrétt and Sprengisandur. On photos, this looks pretty dry, but Iceland is not the Sahara.

^{Source: Johann Dréo, CC-BY-SA, Wikimedia Commons}

A topographic map appears to show plenty of streams in this area, but so do maps in deserts in the USA, even if those streams rarely have water (usually shown dashed but sometimes also when drawn as continuous lines). Should I expect that streams to be seasonal and dried out in September, or can I rest assured that in the chilly climate of Iceland with little evaporation, streams do not actually dry out?