Understanding space weather

From the Sun. To everyday life.

A clearer view.

Space weather is fascinating. A clear explanation is more useful than a dramatic headline.

The observation desk

A window into space weather.

NOAA source report

The estimated planetary Kp index describes geomagnetic activity from 0 to 9. It is not a solar flare measurement or a local forecast.

Planetary geomagnetic activityNOAA SWPC / UTC

Observations are not connected.

—estimated Kp / 9

For the latest readings, open NOAA’s report.

Recent three-hour periods

    Readings appear here when the data service is available.
    Observation ≠ predictionUnderstand the readings

    Source: NOAA Space Weather Prediction Center. Times in UTC. An interval start older than four hours is marked stale. Use official alerts and local guidance for decisions.

    The essentials

    Get to know the difference.

    A solar flare is radiation.

    A flare releases electromagnetic energy from the Sun. Strong flares can disrupt high-frequency radio on Earth’s sunlit side. Flare classes and geomagnetic storm levels describe different things.

    Solar flares, explained

    A geomagnetic storm is a disturbance.

    Changes in the solar wind can disturb Earth’s magnetosphere. Coronal mass ejections and high-speed solar wind streams can contribute. A flare does not automatically mean a geomagnetic storm at Earth.

    Geomagnetic storms, explained

    Kp gives a wider view.

    The estimated planetary Kp index describes geomagnetic activity over three-hour periods. It does not predict your local electricity supply, tell you that equipment is safe, or guarantee an aurora sighting.

    How to read Kp