Solar Flares
Live X-Ray Flux & Flare Alerts
Explanations by Spaceweathertracker staff · Last reviewed · Editorial standards · About
M-class and X-class solar flare detection from the GOES XRS instrument, updated every 2 minutes. Watch our guide to understanding solar flares.
Largest 24h
X-class 24h
M-class 24h
C-class 24h
Solar flares can disrupt GPS accuracy, satellite links, and HF radio. X-class events cause the biggest blackouts; M-class may briefly degrade navigation.
Largest X-ray class · last 24 h
Sunspot Region Tracker
Active sunspot regions reported on the visible solar disk, from NOAA/USAF's daily Solar Region Summary.
NOAA report issued: 2026 Nov 05 0030 UTC · Daily summary, not a real-time image
| Region | Location | Sunspots | Magnetic Class | Flare Risk |
|---|---|---|---|---|
| AR4564 | N03W14 | 5 | Beta | Moderate |
| AR4565 | N15E08 | 5 | Beta | Moderate |
| AR4566 | S06E40 | 12 | Beta-Gamma-Delta | Very High |
| AR4567 | N17W41 | 2 | Beta | Moderate |
Flare risk is a qualitative tier based on each region's real magnetic complexity classification (well-established solar physics: complex Beta-Gamma-Delta regions historically produce the large majority of M/X-class flares) — not a live per-region probability percentage, which this app doesn't have a data source for.
Source: NOAA/USAF Solar Region SummaryNOAA overall flare probability forecast
NOAA's overall probability of at least one C-, M-, or X-class flare occurring anywhere on the visible solar disk, for each of the next forecast days below. This is a whole-disk forecast, not a prediction for any single active region.
| Day | C-class | M-class | X-class | Proton event |
|---|---|---|---|---|
| Wed, Nov 4 | 80% | 30% | 10% | 5% |
| Thu, Nov 5 | 85% | 35% | 10% | 5% |
| Fri, Nov 6 | 85% | 35% | 10% | 5% |
Source: NOAA SWPC
What is a solar flare?
A solar flare is a sudden, intense burst of radiation from the Sun's surface, released when twisted magnetic field lines near a sunspot region snap and reconnect. Flares are classified by peak X-ray brightness on a logarithmic scale — A, B, and C are minor; M-class flares can cause brief radio blackouts on Earth's sunlit side; X-class flares are the most powerful, capable of triggering strong radio blackouts and, when paired with an Earth- directed CME, geomagnetic storms and aurora far from the poles.
NOAA R-scale: radio blackout impact
NOAA's official radio blackout scale, derived from GOES long-channel X-ray flux and tied directly to flare class.
| R-Scale | Level | GOES X-ray flux | Flare class | HF radio blackout impact |
|---|---|---|---|---|
| R1 | Minor | ≥1×10⁻⁵ W/m² | M1 | Weak or minor degradation of HF radio on the sunlit side; brief loss of contact. |
| R2 | Moderate | ≥5×10⁻⁵ W/m² | M5 | Limited HF radio blackout on the sunlit side; loss of contact for tens of minutes. |
| R3 | Strong | ≥1×10⁻⁴ W/m² | X1 | Wide-area HF radio blackout; loss of radio contact for about an hour. |
| R4 | Severe | ≥1×10⁻³ W/m² | X10 | HF radio blackout over most of the sunlit side for one to two hours. |
| R5 | Extreme | ≥2×10⁻³ W/m² | X20 | Complete HF radio blackout across the entire sunlit side, lasting many hours. |
See the Radio Blackout Tracker for the current live R-scale level.
💡 What This Means for You (Plain English Mode)
Live flare data is loading — check back in a moment for a real, current reading.
• Data source: NOAA SWPC
AIA 131Å solar flare footage — NASA SDO, Dec. 4 2014 M6 flare
NASA/SVSRecent flares · Last 7 days
GOES XRS · 34 events| Peak Time (UTC) | Class | Begin | End |
|---|---|---|---|
| Thu 06:12 UTC | B9.1 | Thu 06:10 UTC | Thu 06:15 UTC |
| Thu 05:18 UTC | B9.7 | Thu 05:09 UTC | Thu 05:21 UTC |
| Thu 02:18 UTC | B9.1 | Thu 02:13 UTC | Thu 02:21 UTC |
| Thu 00:13 UTC | B9.4 | Thu 00:04 UTC | Thu 00:15 UTC |
| Wed 17:34 UTC | C2.2 | Wed 17:23 UTC | Wed 17:38 UTC |
| Wed 15:00 UTC | B9.7 | Wed 14:50 UTC | Wed 15:09 UTC |
| Wed 06:54 UTC | C1.2 | Wed 06:43 UTC | Wed 07:02 UTC |
| Tue 22:39 UTC | C1.1 | Tue 22:32 UTC | Tue 22:44 UTC |
| Tue 19:25 UTC | B4.6 | Tue 19:21 UTC | Tue 19:29 UTC |
| Tue 18:28 UTC | B4.7 | Tue 18:23 UTC | Tue 18:32 UTC |
| Tue 16:40 UTC | B4.2 | Tue 16:34 UTC | Tue 16:44 UTC |
| Tue 06:15 UTC | B4.8 | Tue 06:08 UTC | Tue 06:19 UTC |
| Mon 22:08 UTC | B8.0 | Mon 21:59 UTC | Mon 22:17 UTC |
| Mon 21:04 UTC | B5.6 | Mon 20:56 UTC | Mon 21:11 UTC |
| Mon 16:44 UTC | B4.2 | Mon 16:37 UTC | Mon 16:51 UTC |
| Mon 06:08 UTC | B7.7 | Mon 05:56 UTC | Mon 06:18 UTC |
| Sun 18:38 UTC | B4.7 | Sun 18:32 UTC | Sun 18:40 UTC |
| Sun 14:01 UTC | B5.2 | Sun 13:55 UTC | Sun 14:08 UTC |
| Sun 12:36 UTC | C1.1 | Sun 12:29 UTC | Sun 12:39 UTC |
| Sat 20:51 UTC | B4.0 | Sat 20:44 UTC | Sat 21:06 UTC |
NOAA's live flare feed doesn't include a source active-region number, so flares above can't be reliably tagged with a "Source: Region XXXX" badge without risking a wrong attribution. See the Sunspot Region Tracker below for which regions are currently active and their flare risk.
❓ Frequently Asked Questions
What causes a solar flare?▾
Solar flares happen when twisted magnetic field lines near sunspot regions suddenly snap and reconnect, releasing a burst of stored magnetic energy as light and radiation. They are most common around active sunspot groups.
How are solar flares classified?▾
Flares are classed A, B, C, M and X by their peak X-ray flux in the 0.1 to 0.8 nanometre band measured by NOAA's GOES satellites. Each letter is ten times stronger than the one before: C starts at 1e-6 W/m2, M at 1e-5 and X at 1e-4. The number after the letter is a multiplier, so an X2 flare is twice as strong as an X1.
Which flares cause radio blackouts?▾
NOAA's R-scale is set by peak X-ray flux: R1 (minor) begins at M1, R2 at M5, R3 at X1, R4 at X10 and R5 at X20. The blackout affects high-frequency radio on the sunlit side of Earth. Weaker C-class flares do not reach R1.
How soon do flare effects reach Earth?▾
A flare's light and X-rays travel at the speed of light and reach Earth in about eight minutes, so radio effects begin almost immediately. A flare does not itself cause aurora; that needs a coronal mass ejection, which can accompany a flare but often does not and takes hours to days to arrive.
Are solar flares dangerous to people on the ground?▾
No. Flare radiation is absorbed by Earth's atmosphere and magnetic field and does not reach the ground. The effects are on technology, such as high-frequency radio, some GPS accuracy and satellite operations, and on the radiation exposure of astronauts and some high-latitude flights during the strongest events.
Sources
- Solar Flares (Radio Blackouts) — NOAA SWPC — A/B/C/M/X flare classes, each a tenfold step in X-ray flux.
- GOES X-ray Flux — NOAA SWPC — Real-time GOES X-ray measurements used to classify flares.
- NOAA Space Weather Scales (G, S and R) — NOAA SWPC — Official G1–G5, S1–S5 and R1–R5 definitions and average frequency per solar cycle.
- DONKI: Space Weather Database of Notifications, Knowledge, Information — NASA CCMC — NASA's catalogue of CMEs, flares, shocks and geomagnetic storms.
- The biggest solar X-ray flare ever is classified as X28 — ESA (Nov 2003) — The 4 November 2003 flare saturated detectors; classified X28.