How to read an aurora forecast in Iceland

What does Kp tell you?

Kp measures global disturbances in Earth’s magnetic field on a scale from 0 to 9. It describes a three-hour interval, not the brightness of the aurora above your home. Check whether a value is an observation or a forecast.

Avoid making your decision from a single Kp threshold. In Hafnarfjörður, clouds, darkness and the location of activity also matter.

Source: NOAA SWPC — Planetary K-index

The auroral oval is a model

NOAA’s OVATION map models an area of auroral activity. It is short-term guidance, not confirmation of an aurora seen from Iceland. Check the data timestamp and the forecast time.

The green animation in Orbit Atlas demonstration mode illustrates the phenomenon. It is neither a photograph nor a reading of the current sky.

Source: NOAA SWPC — Aurora — 30 Minute Forecast

Check clouds and darkness

On the Icelandic Met Office aurora map, green shows forecast cloud cover and white shows forecast clear areas. Read the legend and selected date and time. The Sun and Moon times displayed on that page are for Reykjavík.

Forecast clouds can differ from the view outside your window. Your own observation describes present conditions; the model helps with planning.

Source: Veðurstofa Íslands — Aurora forecast

Check conditions in Orbit Atlas

1. Open “Your sky today”. In “Place and time”, choose Hafnarfjörður or enter your coordinates and apply the settings.
2. Select the correct time. Use live time for going outside now, or a date within the available forecast for planning.
3. Choose “Check weather and aurora”. Compare timestamps and data availability, then open the vedur.is map.
4. Before leaving, check for actual clear patches. Choose a safe, accessible spot with an open sky and dim your screen.

Missing data is not a quiet forecast

An unavailable source or a time outside the forecast range means information is missing. It does not mean Kp is zero or that no aurora is present. Refresh or consult the source directly. Do not substitute demonstration mode for an observing forecast.