Multi-night planner
Iceland Aurora Trip Planner
Pick your travel dates and see, night by night, how dark the sky gets and how much the moon will interfere. Built for planning a trip weeks ahead, not for tonight's sky.
This planner uses darkness and moon phase only — no weather or Kp/geomagnetic forecast. Heading out in the next few days? Check the live Iceland aurora forecast for tonight's activity and cloud cover.
Plans a window of up to 30nights, starting on any future date. Based on moonlight and civil darkness (the sun 6° below the horizon) only, not a weather or Kp/geomagnetic forecast — check the live aurora forecast and cloud cover before you go.
Choose a valid date range to see the nightly outlook.
Visibility score legend
The score blends how long the sky is in civil darkness — the sun 6° below the horizon — (60% of the score) with how little moonlight there is (40% of the score). It does not use weather, cloud cover, or the Kp/geomagnetic index.
- 75–100 Excellent
- Long dark window, dim moon
- 50–74 Good
- Solid dark window
- 25–49 Fair
- Shorter window or brighter moon
- 0–24 Poor / none
- Little or no usable darkness
Why moon and darkness, not a forecast
Geomagnetic activity and cloud cover cannot be forecast more than a few days out with any real confidence, so a tool that tried to predict them a month ahead would just be guessing. Moon phase and civil darkness, on the other hand, are pure orbital mechanics — the same calculation works just as well for a trip next week or next year. This planner uses that reliable half of the picture to help you choose which nights of a longer trip are worth prioritising for aurora watching, before you narrow down with the live forecast closer to the date.
Darkness is calculated the same way as Saga's daylight hours calculator: civil darkness starts once the sun is at least 6 degrees below the horizon. Moon illumination comes from the moon's position in its roughly 29.5-day cycle around Earth.
Planning the trip itself
A good aurora night still needs somewhere safe to watch from, away from direct light, and a plan for winter roads if you intend to drive after dark. If you would rather not self-drive in the dark, compare northern lights tours, which run on the nights local guides judge best.
Frequently asked questions
- How is the visibility score on this planner calculated?
- Each night's score blends how long the sky is in civil darkness (the sun at least 6 degrees below the horizon) for 60% of the score, with how little moonlight there is that night for 40% of the score. It is a planning heuristic based purely on geometry: the sun's position and the moon's phase. It does not use weather, cloud cover, or the Kp/geomagnetic index.
- Does this tool predict whether I will actually see the northern lights?
- No. It tells you which nights in your trip window are dark enough, for long enough, with little enough moonlight, to give the aurora a fair chance if it appears. Whether it actually appears depends on geomagnetic activity and clear sky, neither of which can be forecast weeks in advance. Check the live aurora forecast and cloud cover close to your travel date.
- What is the best moon phase for seeing the northern lights?
- A new moon, or a night within a few days of one, gives the darkest sky and the best contrast for fainter aurora. A full moon washes out all but the brightest displays, though a strong aurora can still be striking even with a bright moon.
- How far ahead can I plan an aurora trip with this tool?
- You can start on any future date, and each view shows a window of up to 30 nights from that first night. Moon phase and darkness times are pure orbital geometry, so they can be calculated reliably years in advance. Weather and geomagnetic activity cannot be forecast that far out, which is why this planner deliberately leaves them out and points you to the live forecast for anything inside a few days of departure.