How to Read Iceland's Aurora Forecast

The tool locals actually use

The Icelandic Met Office (vedur.is) publishes a dedicated aurora forecast that combines two separate pieces of information into one map: a solar activity index and a cloud cover forecast specific to Iceland. This is the same tool most Icelandic tour guides check before deciding where to drive on a northern lights tour — considerably more useful than a generic global aurora app, because it's built specifically around Icelandic conditions.

The two things the forecast actually shows

1. The activity index (0-9 scale)

This number represents predicted solar/geomagnetic activity — roughly, how strong and active the aurora display is likely to be if skies are clear. A higher number generally means a more vivid, more visible display. But this number alone tells you nothing about whether you'll actually see anything — which is where the second layer matters more than most visitors expect.

2. The cloud cover map

Overlaid on the same map, a green-to-grey shading shows predicted cloud cover across different regions of Iceland for that night. This is the layer that decides your night, not the activity index. A high activity forecast under thick cloud produces nothing visible; a modest activity number under clear skies can still produce a genuinely good show.

How to actually use it

• Check the forecast in the early evening for that same night — conditions and cloud predictions update through the day and become more reliable closer to the time.
• If you're self-driving, look for gaps in cloud cover reasonably close to your location — driving 30-60 minutes toward a clearer patch is a common and often worthwhile strategy.
• Combine this with genuine darkness: even a clear, active forecast won't show much if you're still within Reykjavik's light pollution. See our full Northern Lights guide for broader tips on timing and location.

Setting realistic expectations

No forecast — Icelandic or otherwise — can guarantee a sighting. Weather forecasting generally becomes less reliable more than a day or two out, and Iceland's coastal weather is particularly prone to sudden change. Treat the forecast as a genuinely useful tool for deciding where to go on a given night, not a guarantee of what you'll see once you're there.