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

Sort

Export CSV

Start (UTC)	Peak	End	Duration	Class	Peak flux (W/m²)	Position	Active region
1988-11-09 18:32	18:34	19:05	33 min	M4.5	4E-5	N13W30	5218
1988-11-09 11:03	11:31	11:57	54 min	M9.7	1E-4	N13W29	5218
1988-11-07 10:05	10:05	10:05	0 min	M3	3E-5	S17W47	5212
1988-11-06 17:20	17:23	18:00	40 min	M4.9	5E-5	S20W37	5212
1988-11-01 20:45	20:48	21:06	21 min	M1.6	2E-5	N11E74	5218
1988-11-01 09:55	09:59	10:18	23 min	M3.4	3E-5	N14E81	5218
1988-10-29 13:37	13:39	13:54	17 min	M1	1E-5	S17E63	5212
1988-10-27 17:37	17:40	18:10	33 min	M3.9	4E-5	S19E88	5212
1988-10-19 21:05	21:10	21:22	17 min	M1.1	1E-5	N19E54	5200
1988-10-19 18:04	18:09	19:05	61 min	M1	1E-5	N26E58	5200
1988-10-17 23:33	23:38	00:16	43 min	M1.6	2E-5	N18E77	5200
1988-10-17 15:08	15:09	15:14	6 min	M2	2E-5	N20E84	5200
1988-10-17 13:10	13:25	13:46	36 min	M1	1E-5	N20E79	5200
1988-10-17 03:10	03:11	03:16	6 min	M2.3	2E-5	N19E88	5200
1988-10-13 19:30	19:34	19:48	18 min	M6.4	6E-5	S20W88	5175
1988-10-12 11:07	11:12	11:16	9 min	M1.4	1E-5	—	—
1988-10-12 03:57	04:02	05:10	73 min	X2.5	2E-4	S20W66	5175
1988-10-10 17:03	17:23	17:53	50 min	M2.7	3E-5	S19W47	5175
1988-10-09 22:45	22:52	22:57	12 min	M1	1E-5	—	—
1988-10-06 00:24	00:28	00:50	26 min	M1.6	2E-5	S27W46	5171
1988-10-05 05:21	23:00	05:32	1451 min	M3.3	3E-5	S23W36	5171
1988-10-04 11:26	11:38	11:54	28 min	M1.9	2E-5	—	—
1988-10-03 22:22	22:34	23:19	57 min	X1.1	1E-4	S27W20	5171
1988-10-03 21:32	21:36	21:51	19 min	M1	1E-5	S26W19	5171
1988-10-03 13:53	14:11	14:42	49 min	X3.2	3E-4	S27W16	5171
1988-10-03 12:22	12:26	12:39	17 min	M1.9	2E-5	S28W15	5171
1988-10-01 06:23	06:27	06:32	9 min	M1.8	2E-5	N22W75	5162
1988-09-30 18:00	18:12	20:01	121 min	M1.7	2E-5	S27E25	5171
1988-09-29 04:44	05:01	05:43	59 min	M1.1	1E-5	S27E48	5171
1988-09-28 21:55	22:08	23:09	74 min	M5.7	6E-5	S27E48	5171
1988-09-27 15:07	15:16	16:17	70 min	M7.9	8E-5	S27E65	5171
1988-09-27 08:50	08:56	09:43	53 min	M1.6	2E-5	S23E63	5171
1988-09-24 22:24	22:37	22:42	18 min	M2.3	2E-5	S18E67	5169
1988-09-22 06:05	06:07	06:21	16 min	M2	2E-5	N26E41	5159
1988-09-19 09:15	09:17	09:28	13 min	M1.6	2E-5	N30E76	5159
1988-09-08 16:40	16:41	17:06	26 min	M1.2	1E-5	S25W27	5131
1988-09-08 10:33	10:38	10:51	18 min	M2	2E-5	S23W79	5131
1988-08-26 08:58	09:12	09:30	32 min	M1.2	1E-5	S20E66	5126
1988-08-23 15:57	16:00	16:31	34 min	M2.4	2E-5	N24E90	—
1988-08-08 05:58	06:03	06:56	58 min	M1.3	1E-5	N29W65	5092
1988-08-03 18:34	18:34	19:04	30 min	M1.3	1E-5	N14W64	5090
1988-08-03 08:05	08:34	09:08	63 min	M1.5	2E-5	—	—
1988-08-02 15:21	15:24	16:05	44 min	M1.7	2E-5	N31E10	5092
1988-08-01 03:33	04:24	05:08	95 min	M2	2E-5	N35E30	5092
1988-07-31 05:18	05:27	06:12	54 min	M4	4E-5	N34E41	5092
1988-07-30 06:47	06:48	07:12	25 min	M1.8	2E-5	N28E41	5092
1988-07-29 19:31	19:33	20:15	44 min	M1.6	2E-5	N32E61	5092
1988-07-25 17:28	18:07	18:47	79 min	M1.5	2E-5	S27E50	5084
1988-07-24 04:37	04:49	06:24	107 min	M2.8	3E-5	S21E55	5084
1988-07-12 22:28	22:32	22:40	12 min	M1.1	1E-5	N28W02	5073

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