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

C1.5

2026-10-26 04:36 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) · 10/26/26

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

Catalogued flares

94,047

1975 → 2026-10-26

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

Latest catalogued flare

C1.5

2026-10-26 04:36 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) · 10/26/26

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) · 10/26/26

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) · 10/26/26 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) · 10/26/26 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) · 10/26/26

Year

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Start (UTC)	Peak	End	Duration	Class	Peak flux (W/m²)	Position	Active region
1991-10-13 19:09	19:14	19:19	10 min	M1.1	1E-5	N23E79	6879
1991-10-13 17:05	17:14	17:18	13 min	M6	6E-5	N22E82	6879
1991-10-12 21:09	21:18	21:30	21 min	M1.1	1E-5	—	—
1991-10-12 09:02	09:08	09:25	23 min	M2.9	3E-5	—	—
1991-10-09 05:26	05:37	06:15	49 min	M1.3	1E-5	—	—
1991-10-05 09:21	09:48	11:13	112 min	M1.1	1E-5	S13W48	6850
1991-10-04 18:20	18:29	18:39	19 min	M5.2	5E-5	N09E12	6861
1991-10-04 08:31	08:44	09:08	37 min	M1.2	1E-5	S18W30	6853
1991-10-03 22:59	23:47	00:33	94 min	M1.1	1E-5	—	6853
1991-10-03 05:04	05:23	05:36	32 min	M1.1	1E-5	S11W22	6850
1991-10-03 00:40	00:50	02:55	135 min	M1.2	1E-5	S20W09	6853
1991-10-02 00:23	00:27	00:29	6 min	M1	1E-5	S21E03	6853
1991-10-01 21:27	21:50	21:58	31 min	M1.8	2E-5	S12W08	6850
1991-10-01 09:38	09:44	09:46	8 min	M1.7	2E-5	S12E07	6850
1991-10-01 05:11	05:16	05:30	19 min	M3	3E-5	S22E13	6853
1991-09-30 21:23	21:32	21:42	19 min	M1	1E-5	S12E07	6850
1991-09-29 14:12	14:33	15:42	90 min	M7.3	7E-5	S21E32	6853
1991-09-26 18:45	18:52	19:29	44 min	M1.4	1E-5	S07E46	6848
1991-09-26 10:26	10:36	10:54	28 min	M3.4	3E-5	S19E75	6853
1991-09-26 04:50	05:17	06:50	120 min	M1.7	2E-5	S18E76	6853
1991-09-24 05:49	05:56	06:17	28 min	M6.1	6E-5	S10E88	6848
1991-09-23 15:49	16:00	16:06	17 min	M1	1E-5	S12W59	6841
1991-09-17 16:55	17:04	17:09	14 min	M1.3	1E-5	N08E14	6832
1991-09-10 18:46	19:11	19:37	51 min	M3	3E-5	—	—
1991-09-09 03:55	04:08	04:41	46 min	M2	2E-5	S14W72	6818
1991-09-08 18:35	18:44	19:10	35 min	M1.6	2E-5	—	—
1991-09-08 09:23	09:41	10:22	59 min	M2.7	3E-5	S12E09	6820
1991-09-08 07:05	07:12	07:35	30 min	X1	1E-4	S13W58	6818
1991-09-08 06:13	06:18	06:26	13 min	M1	1E-5	—	—
1991-09-07 23:36	23:54	02:40	184 min	M2.1	2E-5	S11W54	6818
1991-09-07 17:20	17:27	17:59	39 min	X3.3	3E-4	S11W50	6818
1991-09-07 16:19	16:33	17:18	59 min	M1.9	2E-5	S11W51	6818
1991-09-07 10:42	10:50	11:46	64 min	M2.1	2E-5	S11W46	6818
1991-09-07 07:54	08:07	09:08	74 min	M4.1	4E-5	S11W48	6818
1991-09-07 05:25	05:51	06:14	49 min	M2.1	2E-5	S13W45	6818
1991-09-05 19:51	20:07	21:23	92 min	M2.9	3E-5	S19W37	6811
1991-09-05 09:56	10:09	10:21	25 min	M1.6	2E-5	N22W75	6805
1991-09-05 03:23	03:28	03:38	15 min	M2.3	2E-5	N24W72	6805
1991-09-04 23:07	23:11	23:32	25 min	M4.4	4E-5	N24W65	6805
1991-09-04 18:22	18:27	18:57	35 min	M1.5	2E-5	N24W63	6805
1991-09-04 16:36	16:46	17:09	33 min	M1.3	1E-5	N23W62	6805
1991-08-30 23:48	00:03	01:17	89 min	M2.9	3E-5	S20E33	6811
1991-08-29 23:12	23:19	23:39	27 min	M2.6	3E-5	S21E48	6811
1991-08-29 02:59	03:09	03:26	27 min	M3	3E-5	—	—
1991-08-28 13:55	14:03	14:21	26 min	M4.3	4E-5	N11W88	6785
1991-08-27 21:11	21:21	21:30	19 min	M1	1E-5	N12W77	6785
1991-08-26 09:53	10:03	10:28	35 min	M1.5	2E-5	—	—
1991-08-26 08:09	08:16	08:47	38 min	M1.2	1E-5	—	—
1991-08-26 03:34	03:38	03:57	23 min	M1.6	2E-5	N24E59	6805
1991-08-26 01:41	01:46	01:50	9 min	M1.2	1E-5	—	—

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 26, 2026 · SHA-256 d24560b7385e…
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