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

B4.2

2026-10-27 02:20 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) · 10/27/26

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

Catalogued flares

94,061

1975 → 2026-10-27

GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/27/26 Current · provisional

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) · 10/27/26 Current · provisional

Latest catalogued flare

B4.2

2026-10-27 02:20 UTC · AR 14561

GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/27/26

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) · 10/27/26

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) · 10/27/26 Current · provisional

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) · 10/27/26 Current · provisional

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) · 10/27/26

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Start (UTC)	Peak	End	Duration	Class	Peak flux (W/m²)	Position	Active region
1987-08-08 01:33	01:38	01:45	12 min	M1.3	1E-5	S24W21	4835
1987-08-07 23:19	23:33	23:42	23 min	M1.3	1E-5	S25W20	4835
1987-08-07 17:43	17:45	18:10	27 min	M1.3	1E-5	S24W17	4835
1987-07-27 16:11	16:12	16:29	18 min	M2.6	3E-5	S26W72	4826
1987-07-24 07:53	08:04	08:39	46 min	M3	3E-5	—	4826
1987-05-25 01:30	01:42	02:03	33 min	M1.3	1E-5	N30W49	4811
1987-05-24 13:18	13:27	13:48	30 min	M1.2	1E-5	N28W37	4811
1987-04-16 13:44	14:16	16:04	140 min	M1	1E-5	S32W43	4790
1987-04-05 17:31	17:39	17:44	13 min	M1.1	1E-5	S29E90	4787
1986-10-18 23:15	23:43	01:10	115 min	M4.7	5E-5	N22E60	4750
1986-05-04 07:39	08:07	08:39	60 min	M1.2	1E-5	—	4727
1986-04-24 04:07	04:13	04:53	46 min	M2.4	2E-5	N04E04	4726
1986-04-24 01:45	01:47	02:28	43 min	M1.2	1E-5	N04E06	4726
1986-04-23 22:39	22:42	23:20	41 min	M1.1	1E-5	N03E07	4726
1986-03-05 06:06	06:09	07:20	74 min	M1.6	2E-5	—	4717
1986-03-03 11:42	11:54	11:57	15 min	M1.3	1E-5	—	—
1986-02-15 12:04	12:09	12:16	12 min	M1.6	2E-5	—	4713
1986-02-15 09:16	11:03	12:00	164 min	M2.2	2E-5	—	4713
1986-02-14 08:10	08:21	09:25	75 min	M6.4	6E-5	N01W76	4713
1986-02-13 01:46	01:46	01:54	8 min	M1	1E-5	N04W63	4713
1986-02-11 22:03	22:21	23:05	62 min	M1	1E-5	N00W43	4713
1986-02-11 02:32	02:38	03:40	68 min	M1.1	1E-5	N00W30	4713
1986-02-07 09:11	09:29	10:25	74 min	M5.2	5E-5	S10W20	4711
1986-02-06 05:18	05:25	06:53	95 min	X1.7	2E-4	S04W06	4711
1986-02-05 11:37	11:53	13:01	84 min	M3	3E-5	S07E06	4711
1986-02-04 09:27	09:33	09:49	22 min	M6.4	6E-5	S02E68	4713
1986-02-04 06:35	06:40	07:37	62 min	X3	3E-4	S03E21	4711
1986-02-03 19:37	19:40	21:40	123 min	M2.3	2E-5	S09E26	4711
1986-01-16 17:37	17:49	18:14	37 min	M1.3	1E-5	S12W88	4710
1986-01-16 15:16	15:17	15:23	7 min	M6.6	7E-5	S09W86	4710
1986-01-15 05:54	06:10	07:40	106 min	M1.1	1E-5	S09W67	4710
1985-10-26 02:59	03:32	04:14	75 min	M1.8	2E-5	N07W61	4698
1985-07-08 23:26	00:04	00:27	61 min	M2.9	3E-5	—	4671
1985-07-02 18:56	19:33	21:10	134 min	M4.5	4E-5	S15E56	4671
1985-05-13 07:04	07:36	07:48	44 min	M1	1E-5	—	4652
1985-05-02 05:41	05:45	05:53	12 min	M4.9	5E-5	—	4647
1985-04-24 07:14	07:22	08:50	96 min	X1.9	2E-4	N06E27	4647
1985-04-22 14:37	14:40	14:49	12 min	M1	1E-5	N05E49	4647
1985-01-23 06:25	06:40	07:27	62 min	M1.3	1E-5	S12W59	4617
1985-01-21 22:52	23:11	01:37	165 min	X4.7	5E-4	S08W38	4617
1985-01-21 20:27	20:32	21:00	33 min	M1.2	1E-5	S08W38	4617
1985-01-21 15:36	15:53	15:57	21 min	M3.3	3E-5	S09W35	4617
1985-01-21 14:14	14:18	14:49	35 min	M1.2	1E-5	—	4617
1985-01-21 13:10	13:25	14:13	63 min	M2.4	2E-5	S08W34	4617
1985-01-21 03:55	04:06	05:59	124 min	M1.1	1E-5	S11W29	4617
1985-01-21 01:39	02:54	03:53	134 min	M2.2	2E-5	S10W30	4617
1985-01-20 19:39	19:55	20:55	76 min	M4.1	4E-5	S09W24	4617
1984-11-27 23:24	23:51	00:49	85 min	M1.1	1E-5	S08W14	4598
1984-11-27 17:32	17:47	17:56	24 min	M1	1E-5	—	4598
1984-11-10 19:01	19:10	19:34	33 min	M3.7	4E-5	—	4592

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 27, 2026 · SHA-256 5d2e8b2d3452…
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