Solar activity right now
Flare level: B4.8 · Kp 2 (quiet) · tonight up to Kp 2
Right now the Sun's X-ray output sits at B4.8 — quiet, and Earth's geomagnetic field is at Kp 2 (quiet), with tonight's forecast peaking near Kp 2. Data: NOAA GOES X-ray flux and the planetary K-index, refreshed every 15 minutes. We're at solar maximum— the most active phase of the Sun's 11-year cycle.
The Kp index right now
The planetary Kp index is currently 2 (quiet), with tonight's forecast peaking around Kp 2. Kp is a 0–9 scale of global geomagnetic disturbance: 0 is dead calm, 5 is the threshold of a geomagnetic storm, and each step pushes the aurora roughly 2° of latitude further from the poles. NOAA maps Kp 5–9 onto its G1–G5 storm classes.
Kp now
2
Tonight's max
2
Storm level
quiet
Kp index scale (0–9)
What does each Kp value mean? The higher the Kp, the stronger the geomagnetic storm and the further toward the equator the northern lights are visible:
| Kp | NOAA class | Aurora reaches | Effects |
|---|---|---|---|
| 0–2 | — | Only near the poles — Arctic Circle, high Antarctica | Quiet. No noticeable effects. |
| 3 | — | N. Scandinavia, Iceland, N. Alaska, N. Canada | Unsettled. Aurora active at high latitudes. |
| 4 | — | S. Norway, central Sweden/Finland, S. Alaska | Active field, but below storm threshold. |
| 5 | G1 | Scotland, Maine, Michigan, N. Washington | Minor storm. Weak grid fluctuations; aurora seen in northern-tier states. |
| 6 | G2 | Ireland, New York, Chicago, Germany, Poland | Moderate storm. HF radio fade at high latitudes; possible voltage alarms. |
| 7 | G3 | Oregon, Illinois, Pennsylvania, S. England | Strong storm. GPS/HF degraded; grid voltage corrections needed. |
| 8 | G4 | N. California, Alabama, central Europe | Severe storm. Widespread grid problems; satellite drag and orientation issues. |
| 9 | G5 | Florida, Texas, southern Europe, low latitudes | Extreme storm. Grid collapse risk, hours of GPS loss, aurora far into the tropics. |
Aurora reach is a rule of thumb for clear, dark skies looking toward the pole; local light pollution and cloud cover push it back. See the live per-city verdict on the aurora forecast.
What the flare classes mean
| Class | Strength | Typical effects |
|---|---|---|
| A / B | Background | None |
| C | Common | Minor, frequent at solar max |
| M | Moderate | Brief radio blackouts, polar aurora boost |
| X | Extreme | Strong blackouts; CMEs → storms & mid-latitude aurora 1–3 days later |
Frequently asked questions
Is the Sun flaring right now?
The current GOES X-ray level corresponds to a B4.8 flare level — quiet. C-class flares are routine; M-class can cause short radio blackouts; X-class are the big ones that can spark strong aurora displays a day or two later.
What is the Kp index right now?
The planetary Kp index is currently 2 (quiet), with tonight's forecast peaking around Kp 2. Kp 5+ is a geomagnetic storm; the higher the Kp, the further south the aurora reaches.
Does a solar flare mean aurora tonight?
Not immediately. The flare's light arrives in 8 minutes, but the aurora comes from the coronal mass ejection (CME) — a cloud of solar plasma that takes 1–3 days to reach Earth. A big flare today often means storm watches for the following nights.
Are solar flares dangerous on the ground?
Not to people — Earth's atmosphere and magnetic field absorb the radiation. Strong events can disrupt HF radio, GPS accuracy and, in extreme cases, power grids; satellites feel it most, through increased drag and radiation.
When the storm comes
A big flare today is tomorrow's light show: check the aurora forecast for your city (552 cities, live Kp vs your local threshold), enable a free storm alert, or watch the Sun and everything it flings at us on the live 3D map. Clear skies also mean ISS passes and the Moon.
