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

B4.3

2026-10-25 03:33 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) · 10/25/26

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

Catalogued flares

94,036

1975 → 2026-10-25

GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/25/26

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) · 10/25/26

Latest catalogued flare

B4.3

2026-10-25 03:33 UTC · AR 14560

GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/25/26

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) · 10/25/26

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) · 10/25/26 GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/25/26

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) · 10/25/26

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) · 10/25/26

Year

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Start (UTC)	Peak	End	Duration	Class	Peak flux (W/m²)	Position	Active region
2011-04-22 13:47	13:53	14:11	24 min	M1.2	1E-5	S18E35	11195
2011-04-22 02:35	02:57	03:14	39 min	M1.8	2E-5	S18E43	11195
2011-04-15 15:02	15:12	15:28	26 min	M1.3	1E-5	N14W19	11190
2011-03-25 22:08	22:22	22:30	22 min	M1	1E-5	—	11176
2011-03-24 11:01	11:07	11:11	10 min	M1	1E-5	S16E43	11176
2011-03-23 01:03	01:17	01:24	21 min	M1.4	1E-5	—	11176
2011-03-14 23:18	23:22	23:24	6 min	M1	1E-5	—	11169
2011-03-14 18:30	18:52	18:54	24 min	M4.2	4E-5	N18W48	11169
2011-03-12 03:33	03:43	03:48	15 min	M1.3	1E-5	N05W36	11166
2011-03-10 21:34	21:41	21:49	15 min	M1.1	1E-5	—	—
2011-03-09 22:13	22:23	22:29	16 min	X1.5	2E-4	N08W09	11166
2011-03-09 12:17	13:02	13:13	56 min	M1.7	2E-5	N09W06	11166
2011-03-09 09:35	10:07	10:21	46 min	M1.7	2E-5	—	11166
2011-03-08 18:46	19:16	20:19	93 min	M1.4	1E-5	—	11165
2011-03-08 17:08	17:28	17:41	33 min	M4.4	4E-5	—	11165
2011-03-08 09:35	09:44	09:55	20 min	M5.3	5E-5	—	11165
2011-03-08 02:37	02:58	03:20	43 min	M1.5	2E-5	—	11171
2011-03-08 01:24	01:29	01:32	8 min	M1.3	1E-5	S18W79	11165
2011-03-07 20:45	20:50	20:55	10 min	M1.5	2E-5	—	11165
2011-03-07 18:43	19:12	19:58	75 min	M3.7	4E-5	—	11164
2011-03-07 12:45	13:30	13:56	71 min	M1.9	2E-5	—	11166
2011-03-07 08:14	08:20	08:28	14 min	M1.8	2E-5	N23W50	11164
2011-03-07 06:59	07:07	07:15	16 min	M1.4	1E-5	N25W47	11164
2011-03-07 06:49	06:54	06:56	7 min	M1.5	2E-5	S20W78	11165
2011-03-07 04:00	04:13	04:19	19 min	M1.2	1E-5	—	11164
2011-02-28 11:38	11:52	12:03	25 min	M1.1	1E-5	—	11164
2011-02-24 06:23	06:35	06:42	19 min	M3.5	4E-5	—	11163
2011-02-18 19:56	20:04	20:14	18 min	M1.3	1E-5	—	11162
2011-02-18 13:00	13:08	13:15	15 min	M1	1E-5	—	11162
2011-02-18 11:59	12:03	12:06	7 min	M1.4	1E-5	—	11158
2011-02-18 09:23	09:26	09:37	14 min	M1	1E-5	—	11162
2011-02-18 08:55	09:11	09:15	20 min	M6.6	7E-5	—	11158
2011-02-16 13:19	13:25	13:29	10 min	M1.6	2E-5	S20W32	11158
2011-02-16 06:35	06:44	06:55	20 min	M1.1	1E-5	—	11161
2011-02-16 00:32	00:39	00:46	14 min	M1	1E-5	—	—
2011-02-15 00:44	00:56	01:06	22 min	X2.2	2E-4	—	11158
2011-02-14 16:20	16:26	16:32	12 min	M2.2	2E-5	N56W18	11158
2011-02-13 16:28	16:38	16:47	19 min	M6.6	7E-5	S20E04	11158
2011-02-09 00:23	00:31	00:35	12 min	M1.9	2E-5	N17W72	11153
2011-01-27 23:44	00:03	00:10	26 min	M1.3	1E-5	—	11149
2010-11-06 14:27	14:36	14:44	17 min	M5.4	5E-5	S19E58	11121
2010-11-05 11:43	12:29	13:06	83 min	M1	1E-5	—	11121
2010-11-04 22:30	22:58	23:12	42 min	M1.6	2E-5	S20E76	11121
2010-10-16 17:07	17:12	17:15	8 min	M2.9	3E-5	S20W26	11112
2010-08-07 15:55	16:24	16:47	52 min	M1	1E-5	N11E34	11093
2010-06-13 03:30	03:39	03:44	14 min	M1	1E-5	S25W84	11079
2010-06-11 22:30	22:57	23:02	32 min	M2	2E-5	N23W43	11081
2010-05-05 15:13	15:19	15:22	9 min	M1.2	1E-5	N42W37	11069
2010-02-12 16:52	17:08	17:15	23 min	M1.1	1E-5	N28W53	11045
2010-02-12 10:19	10:26	10:28	9 min	M8.3	8E-5	—	11046

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 25, 2026 · SHA-256 a1d99f7354e3…
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