C3.0Moderate — C-classpeak Jul 24, 10:03 PM UTC
Only minor C-class flares — common during an active cycle, with little effect at the ground.
Past 24h · C5
Past 24h · M0
Past 24h · X0
Latest flareC1.9
SUN · SOLAR FLARES
Solar Flare Tracker
A solar flare is a sudden, intense burst of radiation from the Sun's surface — the most powerful explosions in the solar system. The strongest can disrupt radio and, paired with an eruption of solar material, light up the aurora across the planet. Here's what the Sun has fired recently, and what it means.
LIVE · Solar-flare activity (GOES X-ray)Updated Jul 25, 1:23 PM UTC
C1.9Jul 25, 5:44 AM UTC
C2.0Jul 25, 3:51 AM UTC
C1.8Jul 25, 1:41 AM UTC
C3.0Jul 24, 10:03 PM UTC
C2.6Jul 24, 9:05 PM UTC
C1.8Jul 24, 6:47 AM UTC
Source: NOAA Space Weather Prediction Center (GOES X-ray sensor) · flare class is a log scale (A<B<C<M<X, each 10×) · refreshes ~every 10 min.
How flare classes work
Flares are graded by their peak brightness in soft X-rays, on a letter scale where each step is ten times stronger than the last: A, B, C, M, then X. A number after the letter fine-tunes it — an M5 is halfway to an X1. A and B flares are background noise; C flares are minor; M flares can cause brief high-frequency radio blackouts on the Sun-facing side of Earth; and X flares are the big ones, capable of strong blackouts and — if a coronal mass ejection comes with them — a major geomagnetic storm a day or two later.
Flares, the solar wind, and the aurora
A flare alone rarely produces aurora at your latitude — what matters is whether the Sun also hurls a cloud of plasma toward Earth, and whether that cloud's magnetic field points south when it arrives. That's why a big flare is the start of the story, not the end. Watch the solar windover the following day or two, and check tonight's aurora forecast for your city.
Field guides
THE WHOLE STAR
Flares, the solar wind, sunspots and eclipses — the Sun, all on one canvas.