Space weather now: Kp index, geomagnetic storms, and CMEs.

Published May 28, 2026 · Updated September 11, 2026

Current conditions: September 11, 2026, 09:36 UTC. Sources: NOAA GOES X-ray flux and planetary K-index. Rewritten every morning.

As of this morning the strongest solar flare of the past 24 hours was a C1.6, and Kp was 1.7 (quiet). The forecast peak for the next 24 hours is Kp 3. The live dashboard tracks NOAA's values through the day.

Space weather is three measurable things: solar flares, coronal mass ejections, and the geomagnetic storms they cause at Earth. The block above is rewritten each morning from NOAA's records, and the dashboard carries the live NOAA Kp and NASA's event list. The storm side, the Kp index, the G scale, and CMEs, is explained below. For today's flares see solar flare today; for whether you can see aurora tonight see northern lights tonight.

Open the live dashboard

What does space weather track?

Three events, in the order they happen:

Solar flares: sudden bursts of radiation from the Sun, rated by X-ray brightness in classes B, C, M, and X.
Coronal mass ejections (CMEs): clouds of plasma and magnetic field launched into space, sometimes aimed at Earth, traveling at up to about 3,000 km/s.
Geomagnetic storms: disturbances in Earth's magnetic field caused by CMEs and fast solar wind, measured by the Kp index from 0 to 9 and the G1 to G5 storm scale.

Is there a geomagnetic storm today?

The Kp index in the block above answers it. Kp runs from 0 to 9 and measures how disturbed Earth's magnetic field is over each three-hour window. Kp 0 to 3 is quiet, Kp 4 is active, and Kp 5 and above is a storm: G1 minor at Kp 5, G2 moderate at Kp 6, G3 strong at Kp 7, G4 severe at Kp 8, G5 extreme at Kp 9. The higher the number, the farther from the poles the aurora reaches. The Kp your own latitude needs, with a table by region, is on the northern lights tonight page.

The dashboard shows NOAA's current Kp in real time, so you can check conditions before you drive somewhere dark. Clear skies and distance from city light matter as much as the number.

Check the current Kp index

What is a coronal mass ejection, and are there any CMEs today?

A coronal mass ejection, or CME, is a cloud of plasma and magnetic field thrown off the Sun, often from the same active region that just produced a flare. Typical CMEs travel 300 to 1,000 km/s; the fastest on record approached 3,000 km/s. An Earth-directed CME arrives one to three days after launch, and that arrival is what drives Kp up and starts a geomagnetic storm. The dashboard lists recent CMEs from NASA's DONKI catalog with each one's speed, so you can see whether anything is on the way. Flares themselves are graded B, C, M, and X by X-ray brightness; the class table and today's strongest flare are on the solar flare today page.

The Sun right now in the SDO 193 angstrom channel, the corona where coronal holes and eruptions show — The Sun right now at 193 angstroms, straight from NASA SDO. Dark patches are coronal holes, the source of fast solar wind; a bright arc lifting off the edge is an eruption. NASA republishes the frame about every 15 minutes.

What is Solar Cycle 25 doing now?

NOAA's 13-month smoothed sunspot number for Cycle 25 peaked near 161 in October 2024 and had fallen to about 100 by February 2026, so the cycle is past its maximum and declining. The declining phase still produces some of a cycle's strongest geomagnetic storms, driven by recurrent high-speed solar wind streams and CMEs from aging active regions, which is why the Kp above is worth a daily check.

Where does the data come from?

The Kp figure is NOAA SWPC's planetary K-index, live on the dashboard. Flares, CMEs, and storm notices come from NASA's DONKI catalog (Database Of Notifications, Knowledge, Information), which posts events a few hours after they happen, with each CME's speed. There is no account, no ads, and no tracking of any kind in the app. It is free on Google Play (Android 8.0 and up) and the App Store (iOS 13.0 and up, universal iPhone and iPad).

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Common questions.

What is the Kp index?

A 0 to 9 scale of geomagnetic activity measured over three-hour windows. Low is quiet, high means a storm is underway and aurora reaches lower latitudes.

What Kp do I need to see aurora?

It depends on your latitude. Kp 5 often brings aurora to the northern tier of US states. Kp 7 or higher can reach mid latitudes. Near the poles, Kp 3 or 4 may be enough.

What is a CME?

A coronal mass ejection: a cloud of plasma and magnetic field thrown from the Sun. An Earth-directed CME can spark a geomagnetic storm a day or two later.

Is the data free?

Yes. Lumara is free on both stores. The Kp comes from NOAA's public feed and the event list from NASA's public DONKI catalog.