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

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Start (UTC)	Peak	End	Duration	Class	Peak flux (W/m²)	Position	Active region
1981-08-13 22:24	22:35	23:05	41 min	M2	2E-5	N25W29	3259
1981-08-13 19:32	19:36	19:53	21 min	M1.1	1E-5	S11W63	3257
1981-08-13 11:33	11:59	12:13	40 min	M1.1	1E-5	—	3257
1981-08-13 05:57	06:09	06:39	42 min	M5.9	6E-5	S10W41	3257
1981-08-13 05:16	05:22	06:05	49 min	M1.8	2E-5	S08W58	3257
1981-08-13 00:50	00:57	01:34	44 min	M3.6	4E-5	S11W46	3257
1981-08-12 22:30	22:46	22:58	28 min	M1.4	1E-5	—	—
1981-08-12 20:25	20:28	20:56	31 min	M1.4	1E-5	S13E75	3266
1981-08-12 18:43	19:16	20:48	125 min	M2.7	3E-5	S10W37	3257
1981-08-12 08:23	08:28	08:31	8 min	M1	1E-5	—	—
1981-08-12 04:24	04:26	05:20	56 min	X2.6	3E-4	S10W28	3257
1981-08-12 00:21	00:34	01:04	43 min	M2.2	2E-5	S10W27	3257
1981-08-11 22:44	22:59	00:13	89 min	M1	1E-5	S12W29	3257
1981-08-11 12:40	12:52	13:20	40 min	M3.9	4E-5	S11W31	3257
1981-08-11 05:41	05:47	06:39	58 min	M4.6	5E-5	S13W16	3257
1981-08-10 23:44	23:46	00:09	25 min	M4.4	4E-5	S13W24	3257
1981-08-10 04:59	04:59	05:28	29 min	M4.8	5E-5	S13W15	3257
1981-08-08 18:26	18:27	18:48	22 min	M1	1E-5	S13W06	3257
1981-08-07 17:02	17:11	20:20	198 min	M3.9	4E-5	S10E24	3257
1981-08-06 06:18	06:22	07:11	53 min	M1	1E-5	S08E51	3257
1981-08-04 15:55	16:01	16:12	17 min	M1.1	1E-5	—	—
1981-08-04 08:23	08:27	08:43	20 min	M1	1E-5	S10E70	3257
1981-08-03 21:41	21:43	22:24	43 min	M2.9	3E-5	—	3257
1981-08-03 18:15	18:28	18:56	41 min	M7.2	7E-5	—	3257
1981-08-03 14:30	14:52	15:15	45 min	M2.8	3E-5	S11W90	3234
1981-08-03 09:18	09:30	09:40	22 min	M1.2	1E-5	—	3234
1981-08-03 07:56	08:08	08:25	29 min	M1.3	1E-5	—	—
1981-08-03 02:23	02:30	02:44	21 min	M1.1	1E-5	S08W70	3234
1981-07-30 22:50	23:00	23:17	27 min	M2	2E-5	S12W35	3234
1981-07-30 21:26	21:46	22:21	55 min	M5.1	5E-5	S11W33	3234
1981-07-30 18:38	19:00	19:09	31 min	M1.1	1E-5	—	—
1981-07-30 14:06	14:30	14:55	49 min	M1.3	1E-5	—	3234
1981-07-28 18:09	18:12	18:33	24 min	M3.4	3E-5	S10W18	3234
1981-07-27 15:24	15:24	16:48	84 min	X1.5	2E-4	S13E11	3234
1981-07-27 09:35	09:37	10:07	32 min	M2.7	3E-5	S17E20	3234
1981-07-27 04:14	04:32	04:50	36 min	M9.3	9E-5	S13E11	3234
1981-07-27 02:09	02:14	02:37	28 min	M1.4	1E-5	S07W42	3221
1981-07-26 23:04	23:15	23:51	47 min	M2.1	2E-5	S11E05	3234
1981-07-26 21:46	21:49	21:56	10 min	M2.1	2E-5	—	3234
1981-07-26 21:20	21:50	21:59	39 min	M1	1E-5	S15E22	3234
1981-07-26 19:27	19:31	20:17	50 min	M9.9	1E-4	S12E22	3234
1981-07-26 17:09	17:20	17:39	30 min	M1.4	1E-5	—	3234
1981-07-26 16:06	16:18	17:04	58 min	M1.4	1E-5	S14E24	3234
1981-07-26 13:29	13:34	14:03	34 min	M2.1	2E-5	S15E26	3234
1981-07-26 11:44	11:54	12:24	40 min	X3.5	4E-4	S15E27	3234
1981-07-26 09:54	09:56	10:21	27 min	M1.2	1E-5	S15E29	3234
1981-07-26 09:09	09:16	13:28	259 min	M4	4E-5	S14E29	3234
1981-07-26 08:02	08:04	08:42	40 min	M2.1	2E-5	S15E29	3234
1981-07-26 06:20	06:46	07:32	72 min	M2.4	2E-5	S09W33	3221
1981-07-26 05:57	06:07	06:32	35 min	X1	1E-4	S14W18	3234

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