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
1988-07-10 22:29	22:39	23:20	51 min	M2.7	3E-5	S18E89	5074
1988-07-09 21:37	21:46	21:58	21 min	M1.6	2E-5	—	—
1988-07-08 09:47	09:55	10:22	35 min	M4.4	4E-5	N11W90	5062
1988-07-08 05:54	05:56	06:08	14 min	M1.1	1E-5	S20W82	5060
1988-07-07 05:22	05:23	05:44	22 min	M3.3	3E-5	N13W73	5062
1988-07-07 03:58	04:02	04:10	12 min	M1.1	1E-5	N13W72	5062
1988-07-01 22:41	23:00	00:02	81 min	M3	3E-5	S20W13	5060
1988-06-30 07:04	07:06	07:16	12 min	M9.2	9E-5	S16E22	5060
1988-06-29 18:15	18:17	19:15	60 min	M4.1	4E-5	S19E27	5060
1988-06-29 05:34	05:38	06:47	73 min	M6.5	6E-5	S19E24	5060
1988-06-28 22:28	22:50	23:26	58 min	M2.6	3E-5	S21E41	5060
1988-06-28 17:55	17:59	18:51	56 min	M2.1	2E-5	S19E45	5060
1988-06-28 15:26	15:28	15:43	17 min	M2.4	2E-5	S20E41	5060
1988-06-28 09:10	09:24	09:44	34 min	M4.5	4E-5	S21E48	5060
1988-06-28 08:12	08:13	08:18	6 min	M3.2	3E-5	N12E53	5062
1988-06-28 06:15	06:16	06:23	8 min	M1.5	2E-5	S20E50	5060
1988-06-28 02:44	02:45	03:14	30 min	M1.3	1E-5	S23E50	5060
1988-06-27 03:49	03:58	04:07	18 min	M1.3	1E-5	N13E67	5062
1988-06-27 00:49	01:04	01:58	69 min	M1.1	1E-5	S20E66	5060
1988-06-26 11:40	11:45	11:57	17 min	M1.3	1E-5	S18W77	5047
1988-06-25 14:36	14:45	14:57	21 min	M6	6E-5	S20E89	5060
1988-06-25 10:48	10:56	11:42	54 min	M1.3	1E-5	S16W66	5047
1988-06-25 09:09	09:13	09:24	15 min	M1.7	2E-5	S19W65	5047
1988-06-25 06:15	06:25	07:07	52 min	M1.2	1E-5	—	—
1988-06-25 04:18	04:59	05:53	95 min	M3	3E-5	—	—
1988-06-24 19:23	19:28	19:53	30 min	M3.3	3E-5	S21E89	—
1988-06-24 14:44	14:48	16:18	94 min	X5.6	6E-4	—	5047
1988-06-24 14:03	14:48	14:54	51 min	X2.4	2E-4	S17W52	5047
1988-06-24 02:18	02:30	05:01	163 min	X1.3	1E-4	S18W45	5047
1988-06-23 15:53	15:57	16:48	55 min	M8.1	8E-5	S17W35	5047
1988-06-23 06:56	07:27	08:03	67 min	X1.6	2E-4	S19W34	5047
1988-06-22 20:23	20:42	20:59	36 min	M5.2	5E-5	S18W27	5047
1988-06-21 21:39	21:44	21:47	8 min	M1.1	1E-5	—	5047
1988-06-04 04:14	05:45	07:04	170 min	M3.6	4E-5	S26W90	5027
1988-05-29 03:31	03:38	04:34	63 min	M1	1E-5	S24W14	5027
1988-05-27 22:43	22:43	22:53	10 min	M1.1	1E-5	S24W00	5027
1988-05-27 11:43	11:48	12:50	67 min	M2	2E-5	S25E05	5027
1988-05-26 18:32	19:16	20:14	102 min	M1.1	1E-5	S26E16	5027
1988-05-25 23:00	23:01	23:50	50 min	M1	1E-5	S28E30	5027
1988-05-23 10:00	10:06	10:26	26 min	M1.1	1E-5	S26E56	5027
1988-05-20 04:08	04:24	04:58	50 min	M1.3	1E-5	—	—
1988-05-17 17:27	18:30	20:05	158 min	M6	6E-5	—	—
1988-04-23 23:08	23:20	23:33	25 min	M1.7	2E-5	—	4990
1988-04-22 12:07	12:17	12:46	39 min	M1	1E-5	N21W64	4990
1988-04-21 07:16	07:49	08:24	68 min	M2.3	2E-5	N19W52	4990
1988-04-20 08:02	08:29	09:40	98 min	M1	1E-5	N21W40	4990
1988-04-18 03:09	03:28	03:48	39 min	M1.7	2E-5	N20W14	4990
1988-04-17 22:21	23:05	23:49	88 min	M3.1	3E-5	S34W56	4996
1988-04-17 02:29	02:37	03:03	34 min	M1.2	1E-5	N24E05	4990
1988-04-16 19:22	19:24	19:49	27 min	M1.2	1E-5	N25E09	4990

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