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Space Weather

What Is the Kp Index?

3 min read

The Kp index is a 0–9 planetary measure of geomagnetic disturbance over three-hour intervals.

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Use this page to understand Kp index. Use the live dashboard to see current alerts, infrastructure stress, weather, wildfire, travel, public-health, supply-chain, and stability indicators in one place.

Quick answer / What to check next

Quick answer

The Kp index is a global scale used to summarize geomagnetic activity over three-hour periods.

What this signal means

It helps users understand whether space weather is quiet, unsettled, storm-level, or potentially relevant to technology systems.

What to check on HazardNow

Current and forecast Kp, SWPC alerts, geomagnetic storm scale, latitude, radio/GPS context, and official technical guidance.

Verify with official source

NOAA Space Weather Prediction Center

Quick read

Useful for
Quickly sizing geomagnetic activity and aurora potential.
Watch
current Kp, forecast Kp, timing, latitude, and SWPC alerts.
Confirm with
NOAA SWPC Kp forecasts and alerts.
Remember
Kp is global and coarse; local impacts need more context.

What the Kp number means

Kp condenses magnetometer observations into a quasi-logarithmic planetary index. Higher values indicate stronger geomagnetic disturbance and generally lower-latitude aurora potential.

Because Kp is global and time-binned, it is best used as a severity overview beside SWPC watches, warnings, and system-specific notices.

Visual reference

Kp scale

Kp rises from quiet conditions to major geomagnetic storm levels.

Kp 0–3
Kp 4
Kp 5
Kp 6–7
Kp 8–9

Official sources to verify

Use these links to verify current source text, update timing, and agency caveats.

Last reviewed: . This page explains general preparedness information and does not replace official instructions.

FAQ

Is kp index a live value on this page?

No. This Learn page is evergreen education. Open the HazardNow dashboard and primary source links for current public context.

What should I do if this signal looks concerning?

Use it as a prompt to verify official sources, providers, operators, or local authorities. HazardNow is informational only.

Related terms

Check the live HazardNow dashboard

Use this page to understand Kp index. Use the live dashboard to see current alerts, infrastructure stress, weather, wildfire, travel, public-health, supply-chain, and stability indicators in one place. Focus on geomagnetic-storm, solar-flare-radio-blackout in the live view.