Sun · flares

A Sun that bursts

Flares are sudden releases of magnetic energy above active regions. The flashes in this view recall the classes of the strongest flares in the GOES catalogue (X, M); their positions are illustrative.

Latest catalogued flare

B4.3

2026-10-25 03:33 UTC

Strongest in the catalogue

X28

2003-11-04

X-class flares

558

1975 → 2026

GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/25/26

Illustrative rendering: procedural prominence loops and flashes; classes from the GOES catalogue below.

Catalogued flares

94,036

1975 → 2026-10-25

GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/25/26

X-class flares

558

7954 M-class

GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/25/26

Latest catalogued flare

B4.3

2026-10-25 03:33 UTC · AR 14560

GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/25/26

Strongest in the catalogue

X28

2003-11-04 18:29 UTC · S19W83

GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/25/26

X- and M-class flares per year GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/25/26 GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/25/26

Show the data as a table

Number of flares per calendar year in the GOES catalogue (NOAA). The current year is provisional; 2020 is marked “instrument change”: since December 2019 the flux is no longer reduced by the 0.7 factor, which raises classes by about 40%.

C-class flares per year GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/25/26

Show the data as a table

Detection of C-class flares depends on the background level, hence on the cycle phase and the instrument; these counts are less homogeneous than those of M and X classes.

Ten strongest flares (peak flux derived from the class)

#	Class	Start (UTC)	Peak	Peak flux (W/m²)	Position	Active region
1	X28	2003-11-04 18:29	18:50	3E-3	S19W83	10486
2	X20	1989-08-15 23:08	23:17	2E-3	S18W84	5629
3	X20	2001-04-02 19:32	19:51	2E-3	—	—
4	X17	2003-10-28 08:51	10:10	2E-3	—	10486
5	X17	2005-09-07 15:17	15:40	2E-3	S11E77	10808
6	X15	1989-03-06 12:54	13:10	2E-3	N35E69	5395
7	X14	2001-04-15 11:19	11:50	1E-3	S20W85	9415
8	X13	1984-04-24 21:56	22:01	1E-3	S12E43	4474
9	X13	1989-10-19 11:29	11:55	1E-3	S27E10	5747
10	X12	1982-06-06 14:30	14:54	1E-3	S09E25	3763

The peak flux (0.1–0.8 nm, W/m²) is derived from the published class, e.g. X28 = 28 × 10⁻⁴ W/m²; the GOES detectors saturated above X17 before 2003, so the 4 November 2003 flare is an estimate.

Filterable catalogue GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/25/26

Year

Minimum class

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Start (UTC)	Peak	End	Duration	Class	Peak flux (W/m²)	Position	Active region
2005-09-16 17:18	17:36	17:48	30 min	M3.5	4E-5	S11W37	10808
2005-09-16 15:35	15:48	16:10	35 min	M1.3	1E-5	S11W33	10808
2005-09-15 23:41	23:49	23:56	15 min	M4.4	4E-5	S13W26	10808
2005-09-15 16:55	17:10	17:26	31 min	M1	1E-5	S11W19	10808
2005-09-15 06:30	06:38	06:46	16 min	X1.1	1E-4	S12W14	10808
2005-09-14 23:52	00:12	00:18	26 min	M1.3	1E-5	—	—
2005-09-14 08:05	08:38	08:54	49 min	M4.6	5E-5	—	—
2005-09-13 21:15	21:22	21:30	15 min	X1.7	2E-4	S10E04	10808
2005-09-13 17:19	17:27	18:57	98 min	X1.5	2E-4	S09E10	10808
2005-09-13 08:41	09:21	09:24	43 min	M1.3	1E-5	—	—
2005-09-12 18:05	18:09	18:11	6 min	M1.5	2E-5	S11E24	10808
2005-09-12 06:37	07:03	07:20	43 min	M6.1	6E-5	S11E25	10808
2005-09-12 04:56	05:01	05:05	9 min	M1.3	1E-5	S11E33	10808
2005-09-12 02:49	03:05	03:27	38 min	M1.5	2E-5	—	—
2005-09-11 18:29	18:40	18:49	20 min	M1.3	1E-5	—	—
2005-09-11 10:44	11:12	11:53	69 min	M3	3E-5	—	10808
2005-09-11 00:29	00:35	00:40	11 min	M3.4	3E-5	S12E41	10808
2005-09-10 19:30	20:11	20:43	73 min	X2.1	2E-4	S13E47	10808
2005-09-10 17:10	17:36	17:50	40 min	M4.1	4E-5	S12E45	10808
2005-09-10 14:34	14:43	14:51	17 min	X1.1	1E-4	S11E47	10808
2005-09-10 06:59	07:07	07:31	32 min	M1.9	2E-5	S12E51	10808
2005-09-10 04:06	04:14	04:17	11 min	M3.7	4E-5	S11E51	10808
2005-09-09 17:13	18:04	18:36	83 min	X6.2	6E-4	S10E58	10808
2005-09-09 15:32	15:51	16:10	38 min	M1.9	2E-5	S11E60	10808
2005-09-09 07:42	07:59	08:08	26 min	X3.6	4E-4	S11E66	10808
2005-09-09 03:32	03:48	04:00	28 min	M6.2	6E-5	S10E66	10808
2005-09-09 02:46	03:03	03:12	26 min	M1.8	2E-5	S10E67	10808
2005-09-09 00:43	01:00	01:07	24 min	X1.1	1E-4	S12E68	10808
2005-09-09 00:33	00:36	00:39	6 min	M1.1	1E-5	S13E66	10808
2005-09-09 00:08	00:19	00:29	21 min	M1	1E-5	S13E68	10808
2005-09-08 18:52	19:06	19:17	25 min	X5.4	5E-4	S11E74	10808
2005-09-08 18:23	18:29	18:41	18 min	M2.1	2E-5	S12E70	10808
2005-09-08 14:49	15:03	15:11	22 min	M2.1	2E-5	S12E74	10808
2005-09-07 15:17	15:40	16:03	46 min	X17	2E-3	S11E77	10808
2005-09-06 17:32	20:02	22:44	312 min	M1.4	1E-5	—	—
2005-08-28 08:17	08:28	08:37	20 min	M1.6	2E-5	N09E36	10803
2005-08-25 02:31	02:40	02:45	14 min	M6.4	6E-5	N09E80	10803
2005-08-23 12:19	12:44	14:08	109 min	M2.7	3E-5	S14W90	10798
2005-08-22 14:46	15:27	16:02	76 min	M5.6	6E-5	S13W65	10798
2005-08-21 22:44	23:33	00:18	94 min	M2.6	3E-5	S11W54	10798
2005-08-03 02:54	03:06	03:11	17 min	M3.4	3E-5	S13E45	10794
2005-08-02 16:22	16:31	16:37	15 min	M4.2	4E-5	S12E47	10794
2005-08-01 11:00	11:51	12:29	89 min	M1	1E-5	N13E32	10792
2005-07-31 10:15	10:24	10:33	18 min	M1.1	1E-5	N13E45	10792
2005-07-30 04:17	04:35	05:01	44 min	X1.3	1E-4	N12E61	10792
2005-07-28 19:39	20:08	20:24	45 min	M4.8	5E-5	N09E82	10792
2005-07-27 22:01	22:30	22:54	53 min	M1	1E-5	N09E90	10792
2005-07-27 02:33	03:02	03:30	57 min	M3.7	4E-5	N11E90	10792
2005-07-16 01:27	01:38	01:45	18 min	M1	1E-5	S10W72	10790
2005-07-14 20:50	20:57	21:02	12 min	M1.1	1E-5	N09W90	10786

Method and sources

The catalogue reproduces the NOAA (SWPC/NGDC) GOES event lists compiled yearly by the NASA GSFC Hesperia centre: start, peak and end (UT), class, heliographic position and active region when known. The class encodes the peak flux in the 0.1–0.8 nm band: C = 10⁻⁶ W/m², M = 10⁻⁵, X = 10⁻⁴, times the number (M2.3 = 2.3 × 10⁻⁵ W/m²).

Lines without an X-ray class (optical or sub-threshold events) are not imported. The last two years are re-read on each import; duplicates are rejected by start time and class. Yearly counts are computed from the imported catalogue.

Reading these data

Until December 2019 NOAA applied a 0.7 factor to the XRS-B flux of GOES 8 to 15; since GOES-16 became the primary satellite the raw flux is used. For the same physical flux, a class after 2020 is therefore about 1.4 times higher (Janssens et al., 2025). Counts before and after 2020 are not directly comparable.

SOURCES OF THIS PAGE

GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC): NOAA SWPC/NGDC GOES X-ray flare event lists (1975–), yearly compilations by K. Tolbert, NASA GSFC Hesperia. Flare classes as reported by NOAA at the time: until December 2019 the XRS-B flux carried a 0.7 scaling factor (Janssens et al., 2025). · source page ↗
Licence : U.S. Government work, public domain (NOAA/NASA) · retrieved on Oct 25, 2026 · SHA-256 a1d99f7354e3…
Janssens (2025): Janssens, J., et al. (2025). Solar flare rates and probabilities based on the McIntosh classification: impacts of GOES/XRS rescaling and recalibration. Journal of Space Weather and Space Climate. · doi:10.1051/swsc/2025007
Licence : Published literature; cited

Solar flares GOES X-ray flare catalogue since 1975

A Sun that bursts