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

Minimum class

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Start (UTC)	Peak	End	Duration	Class	Peak flux (W/m²)	Position	Active region
1988-12-18 15:35	15:41	15:58	23 min	M1.4	1E-5	S22E19	5282
1988-12-18 08:13	08:15	08:46	33 min	M1	1E-5	N22E07	5278
1988-12-17 16:32	16:36	19:11	159 min	M1.5	2E-5	S15W35	5272
1988-12-17 04:40	04:43	05:00	20 min	M2.7	3E-5	N27E31	5278
1988-12-17 03:58	04:00	04:53	55 min	M3.2	3E-5	N28E30	5278
1988-12-17 02:44	02:46	03:06	22 min	M2.8	3E-5	S32W23	5273
1988-12-16 07:38	07:41	07:50	12 min	X4.7	5E-4	N26E37	5278
1988-12-15 20:23	20:31	21:06	43 min	M1.5	2E-5	N20E14	5279
1988-12-15 06:24	06:29	07:10	46 min	M1.3	1E-5	—	—
1988-12-15 03:46	04:05	05:09	83 min	X1.1	1E-4	N27E59	5278
1988-12-14 19:35	19:58	20:10	35 min	M1	1E-5	S33E08	5273
1988-12-14 16:29	16:43	17:21	52 min	M1.3	1E-5	N27E62	5278
1988-12-14 12:37	12:37	12:54	17 min	M2.1	2E-5	N30E63	5278
1988-12-13 00:30	00:37	01:15	45 min	M2	2E-5	N25E74	5278
1988-12-11 08:02	09:29	09:43	101 min	M1	1E-5	S32E67	5275
1988-12-10 21:59	22:00	22:04	5 min	M1.8	2E-5	S34E73	5275
1988-12-10 15:51	15:54	15:58	7 min	M1.1	1E-5	—	—
1988-12-10 13:20	13:50	16:17	177 min	M2.2	2E-5	—	—
1988-12-09 20:17	20:20	20:25	8 min	M2.6	3E-5	N21E09	5265
1988-12-09 06:32	06:35	06:51	19 min	M3.8	4E-5	N20E13	5265
1988-12-09 02:16	02:17	02:33	17 min	M2.2	2E-5	N21E20	5265
1988-12-07 22:35	22:40	23:00	25 min	M1	1E-5	S17W90	5254
1988-11-27 21:07	21:30	22:42	95 min	M6.5	6E-5	S18E45	5254
1988-11-27 07:01	07:12	07:20	19 min	M1.4	1E-5	N29W90	5241
1988-11-26 22:30	22:38	23:29	59 min	M1.2	1E-5	S17E57	5254
1988-11-24 20:58	21:07	21:26	28 min	M1.5	2E-5	S20E87	5254
1988-11-21 21:50	21:59	22:44	54 min	M1.6	2E-5	N14W56	5235
1988-11-16 18:57	19:11	19:35	38 min	M1.2	1E-5	N32W06	5229
1988-11-16 16:29	16:34	17:21	52 min	M1.1	1E-5	N31W07	5229
1988-11-16 14:00	14:00	14:37	37 min	M2.7	3E-5	N19E37	5240
1988-11-16 13:11	13:37	13:54	43 min	M1.1	1E-5	N31W02	5229
1988-11-16 08:19	08:35	08:50	31 min	M1	1E-5	—	—
1988-11-16 05:31	23:00	05:55	1464 min	M2.1	2E-5	N32W00	5229
1988-11-16 04:00	04:04	04:24	24 min	M1.2	1E-5	—	—
1988-11-16 03:15	23:00	03:50	1475 min	M4.7	5E-5	N33W13	5229
1988-11-15 21:15	21:23	21:25	10 min	M2	2E-5	N36W01	5229
1988-11-14 18:44	18:47	19:25	41 min	M4	4E-5	N23E64	5240
1988-11-14 15:40	15:46	16:23	43 min	M3.4	3E-5	N31E09	5229
1988-11-14 12:44	13:37	14:58	134 min	M2.2	2E-5	N31E11	5229
1988-11-14 10:50	11:06	11:44	54 min	M1.3	1E-5	S23W35	5227
1988-11-14 06:39	06:56	07:23	44 min	M1.4	1E-5	—	—
1988-11-14 02:23	03:15	04:20	117 min	M1.3	1E-5	S23W30	5227
1988-11-14 00:46	00:55	01:30	44 min	M2.3	2E-5	N21E72	5240
1988-11-13 21:52	22:09	23:05	73 min	M3.2	3E-5	S23W27	5227
1988-11-13 20:48	21:05	21:52	64 min	M3.8	4E-5	N34E27	5229
1988-11-13 19:22	19:25	19:28	6 min	M1.2	1E-5	N34E27	5229
1988-11-13 15:28	15:33	16:22	54 min	M3.4	3E-5	N31E24	5229
1988-11-13 03:50	04:37	05:39	109 min	M7	7E-5	N33E37	5229
1988-11-12 15:05	15:08	16:05	60 min	M5.1	5E-5	N35E44	5229
1988-11-10 05:04	05:13	05:45	41 min	M9.5	1E-4	N13E83	5231

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