Space weather and aurora forecast: track solar flares, CMEs, and the Kp index live.
Current conditions: August 29, 2026, 11:38 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 B6.1, and Kp is 3.7 (quiet). The forecast peak for the next 24 hours is Kp 5.7. The dashboard below tracks the live values through the day.
The Sun is not quiet. It throws flares of radiation, hurls coronal mass ejections across the solar system, and stirs up geomagnetic storms that paint the sky with aurora and, in strong cases, disrupt satellites, radio, and power grids. Lumara shows all of it live, pulled from NASA's space weather database, free and with no account.
The three things space weather tracks.
Space weather sounds abstract, but it comes down to three measurable events, and Lumara surfaces all three:
- 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.
Can you see the northern lights tonight?
Most of the time, aurora visibility comes down to one number: the Kp index. The higher it climbs, the farther from the poles the aurora reaches. Your latitude decides how high the Kp needs to be for you.
| Kp index | Storm level | Where aurora may be visible |
|---|---|---|
| 0 to 3 | Quiet | High latitudes near the poles only |
| 4 | Active | Far northern latitudes, dark skies |
| 5 | G1 minor storm | Northern tier of US states, northern Europe |
| 6 to 7 | G2 to G3 | Pushes toward mid latitudes |
| 8 to 9 | G4 to G5 | Rare strong storms, aurora possible far south |
Lumara shows the current Kp index and recent geomagnetic activity 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.
Solar flare classes, explained.
Solar flares are graded by their peak X-ray output. Each class is ten times more intense than the one below it.
| Class | What it means |
|---|---|
| B | Background level. Minor, no real effect on Earth. |
| C | Small. Few noticeable effects at the surface. |
| M | Medium. Can cause brief radio blackouts near the poles and minor radiation storms. |
| X | The strongest. Can trigger planet-wide radio blackouts, and with a CME, major geomagnetic storms. |
Lumara labels the latest flare by class, so you can tell at a glance whether the Sun is calm or active without reading a forecast bulletin.
Solar Cycle 25, post-maximum.
Solar Cycle 25 peaked in late 2024 into early 2026, and post-maximum has not meant quiet. The Sun produced 104 X-class flares through May 31, 2026, and on January 18-19, 2026 it unleashed an S4 radiation storm, about 37,000 pfu, the cycle's first S4. The declining phase of a solar cycle regularly produces some of its strongest storms, so the numbers on this page are worth a daily check, not just a glance during a headline event.
How Lumara tracks space weather.
Lumara pulls live data from NASA's DONKI feed, the Database Of Notifications, Knowledge, Information that space weather forecasters use. It shows recent flares, CMEs with their speed, and the current geomagnetic storm level, updated in real time. There is no account, no ads, and no tracking of any kind in the app. The app is free on Google Play (Android 8.0 and up) and the App Store (iOS 14.0 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, and the space weather data comes from NASA's public DONKI feed.
Common questions.
What Kp index do I need to see the northern lights?
It depends on your latitude. At Kp 5 (a G1 storm) aurora is often visible across the northern tier of US states and similar latitudes. At Kp 7 or higher (G3 and above) it can reach mid latitudes. Closer to the poles, aurora can appear at Kp 3 or 4. Dark skies away from city light help at any level.
What is a coronal mass ejection?
A coronal mass ejection, or CME, is a large cloud of plasma and magnetic field launched from the Sun into space, sometimes at up to 3,000 km/s. When a CME is aimed at Earth, it can trigger a geomagnetic storm a day or two later. Lumara tracks recent CMEs, including their speed, from NASA's DONKI database.
Is Lumara's space weather data free?
Yes. Lumara is free on Google Play and the App Store, with no ads, no account, and no tracking. The space weather data comes live from NASA's public DONKI feed.