What causes the Aurora Borealis?

The Aurora Borealis is caused by charged particles from the solar wind colliding with gases in the Earth's atmosphere, guided by the planet's magnetic field.

Solar wind is a constant stream of charged particles released from the Sun's upper atmosphere that travels through the solar system.

Why is the Earth's magnetic field important for auroras?

The Earth's magnetic field, or magnetosphere, protects the planet and channels charged solar particles towards the North and South magnetic poles.

When is the best time to see the Northern Lights?

The best time is during high solar activity (high Kp index) on clear, dark nights away from light pollution, typically in northern latitudes.

Aurora Tracker: Northern Lights & Solar Activity

Q: What is the Kp index?

The Kp index is a scale from 0 to 9 used to measure geomagnetic activity. A higher Kp index indicates a greater chance of seeing the Northern Lights further south.

Live Connection

Syncing...

Planetary Kp Index

Scale G0

Initializing Data...

Fetching latest planetary geomagnetic measurements from NOAA...

Local Visual Probability

--% Sight Chance

Calculating...

Calculating probability based on the OVATION Prime model.

Target Coordinates

--.°, --.°

Magnetic Region

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Observer Intelligence for your area

Processing environmental and geomagnetic variables...

NOAA Space Weather G-Scale Official Standard

G0 Kp 0-4

Quiet / Active

Normal magnetic conditions. Aurora at high latitudes.

G1 Kp 5

Minor Storm

Aurora visible in Northern UK and Northern US border.

G2 Kp 6

Moderate Storm

Aurora visible across Midlands UK and mid-US states.

G3 Kp 7

Strong Storm

Aurora potentially visible to Southern UK/Europe/US.

G4/5 Kp 8-9

Severe / Extreme

Rare event. Aurora visible deep into lower latitudes.

A split graphic shows two illuminated globes side by side against a dark space background, illustrating how the geomagnetic Kp index relates to auroral visibility at different latitudes.

Geomagnetic Kp Index and G-Scale Map

Aurora Tracker: Frequently Asked Questions

What is the Kp Index?

The Kp index is a scale used to measure geomagnetic activity on a scale from 0 to 9. It acts as a general indicator of how strong the aurora might be and how far south it may be visible. Higher values indicate more intense geomagnetic activity, pushing the aurora further toward the equator.

What causes the Kp Index to increase?

Geomagnetic activity increases whenever Earth is struck by disturbances from the Sun. These events twist and stretch the planet’s magnetic field, releasing energy into the atmosphere that creates the glowing auroras. Common causes include:

High-speed solar wind streams: Fast-flowing particles released from coronal holes.
Solar Flares: Sudden, intense bursts of radiation.
Coronal Mass Ejections (CMEs): Large eruptions of solar plasma.
Geomagnetic Storms: Major disturbances in Earth's magnetosphere caused by solar activity.

What Kp level do I need to see the Aurora?

The required Kp level depends entirely on your location:

Arctic Regions: Even a low Kp of 1–2 is often enough for strong, vibrant displays.
Lower Latitudes: You will generally need a higher Kp (typically 5 or above) to see the aurora further south.

Is the Kp Index the only thing that matters for an Aurora hunt?

No. While the Kp index is a great tool for understanding overall conditions, it doesn't tell the whole story. For a successful hunt, you must also consider real-time factors such as:

Bz (Interplanetary Magnetic Field): Needs to be pointing "South" to allow solar energy into our atmosphere.
Solar Wind Speed: Faster speeds generally lead to more dynamic displays.
Cloud Cover: Even the strongest aurora cannot be seen through thick clouds.

How should I use this tracker?

Use the Kp index to understand the general potential for an aurora display on a given night, but always rely on live data (such as Bz and wind speed) and local weather forecasts when planning your actual departure.

A night-time photograph taken in Iceland showing vivid green aurora borealis sweeping across the sky.

Northern lights (as seen over Iceland)

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