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

Year

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Start (UTC)	Peak	End	Duration	Class	Peak flux (W/m²)	Position	Active region
1988-04-15 19:12	19:22	19:42	30 min	M2	2E-5	N23E21	4990
1988-04-15 18:00	18:06	19:10	70 min	M1.5	2E-5	S17W08	4992
1988-04-14 17:34	17:42	18:17	43 min	X1.2	1E-4	N25E37	4990
1988-04-12 15:07	15:08	15:39	32 min	M1.4	1E-5	N24E68	4990
1988-03-25 10:17	10:22	10:29	12 min	M2	2E-5	S30W80	4964
1988-03-25 04:15	04:26	04:48	33 min	M2	2E-5	—	—
1988-03-24 15:34	15:35	15:49	15 min	M1.2	1E-5	S26W69	4964
1988-03-24 09:19	09:26	09:41	22 min	M4.3	4E-5	N21E87	4975
1988-03-18 09:04	09:05	09:19	15 min	M1	1E-5	S24E04	4964
1988-03-17 19:46	19:53	20:59	73 min	M2.2	2E-5	S23E07	4964
1988-03-17 09:52	09:58	10:11	19 min	M3.2	3E-5	—	—
1988-03-16 20:29	20:33	21:03	34 min	M2.4	2E-5	S24E21	4964
1988-03-16 17:38	17:54	18:16	38 min	M8.2	8E-5	S24E21	4964
1988-03-16 14:41	14:46	15:15	34 min	M1.3	1E-5	S24E27	4964
1988-03-16 13:12	13:14	13:24	12 min	M2.1	2E-5	S24E25	4964
1988-03-16 08:45	08:47	09:13	28 min	M1	1E-5	S22E29	4964
1988-03-16 04:48	04:55	05:23	35 min	M2.4	2E-5	S22E29	4964
1988-03-16 03:17	03:23	03:32	15 min	M1.1	1E-5	—	—
1988-03-16 01:44	01:51	02:16	32 min	M1.4	1E-5	S26E34	4964
1988-03-15 21:16	21:19	21:43	27 min	M3.7	4E-5	S24E34	4964
1988-03-15 19:39	19:45	20:05	26 min	M4.4	4E-5	S22E34	4964
1988-03-15 15:07	15:17	16:40	93 min	M6.5	6E-5	S24E41	4964
1988-03-15 10:45	10:54	11:06	21 min	M5.9	6E-5	S23E47	4964
1988-03-15 08:21	08:32	08:41	20 min	M3.3	3E-5	S23E46	4964
1988-03-15 07:24	07:26	07:46	22 min	M2.5	2E-5	S22E45	4964
1988-02-20 03:05	03:14	04:32	87 min	M1.1	1E-5	S08W68	4951
1988-01-14 13:58	14:02	14:34	36 min	M2.3	2E-5	S37E48	4925
1988-01-14 08:05	08:19	08:45	40 min	M1.3	1E-5	S38E51	4925
1988-01-02 20:11	20:35	23:09	178 min	X1.4	1E-4	S34W18	4912
1987-12-26 18:40	19:16	20:22	102 min	M1.1	1E-5	S34E62	4912
1987-12-26 17:04	17:05	17:27	23 min	M1.8	2E-5	S33E66	4912
1987-11-21 16:55	17:05	18:01	66 min	M3.5	4E-5	S23E16	4891
1987-11-20 22:31	22:37	00:11	100 min	M1.3	1E-5	S21E25	4891
1987-11-20 03:12	03:18	04:35	83 min	M1.3	1E-5	S21E35	4891
1987-11-19 06:41	06:46	07:59	78 min	M1.1	1E-5	S21E42	4891
1987-11-18 02:17	02:19	02:26	9 min	M1	1E-5	S22W07	4890
1987-11-07 19:28	19:30	19:45	17 min	M1.2	1E-5	N31W90	4875
1987-11-05 22:34	22:35	22:39	5 min	M2.1	2E-5	N29W75	4875
1987-11-05 03:56	03:58	04:12	16 min	M3.1	3E-5	N30W73	4875
1987-11-04 22:23	22:25	22:32	9 min	M1.5	2E-5	N27W62	4875
1987-11-04 16:13	16:15	16:41	28 min	M1.3	1E-5	N28W67	4875
1987-10-17 11:21	11:23	12:01	40 min	M1.4	1E-5	S25W36	4870
1987-10-16 08:50	09:02	09:10	20 min	M1.7	2E-5	—	4866
1987-09-20 23:57	00:04	00:14	17 min	M1.3	1E-5	S35W64	4853
1987-08-23 20:35	20:57	21:48	73 min	M1.3	1E-5	N14E52	4845
1987-08-22 14:39	14:48	15:17	38 min	M1.3	1E-5	N15E67	4845
1987-08-22 07:30	22:00	07:44	1454 min	M1.4	1E-5	N19E77	4845
1987-08-13 11:38	11:41	11:55	17 min	M1.2	1E-5	S23E71	4842
1987-08-09 11:54	11:55	12:01	7 min	M1.3	1E-5	S23E81	4839
1987-08-08 11:46	11:51	12:15	29 min	M1.3	1E-5	S26W26	4835

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