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

Minimum class

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Start (UTC)	Peak	End	Duration	Class	Peak flux (W/m²)	Position	Active region
1991-11-06 22:53	22:59	23:07	14 min	M2.8	3E-5	S13W31	6906
1991-11-06 18:22	18:31	18:38	16 min	M1.2	1E-5	S15W23	6906
1991-11-06 03:45	03:50	04:01	16 min	M4.7	5E-5	S14W20	6906
1991-11-05 21:04	21:10	21:19	15 min	M1.1	1E-5	S14W16	6906
1991-11-04 21:52	22:23	22:50	58 min	M3.4	3E-5	—	—
1991-11-04 03:25	03:55	05:05	100 min	M1	1E-5	S19W89	6892
1991-11-01 19:09	19:29	20:07	58 min	M1.4	1E-5	S11W64	6891
1991-10-31 08:06	08:12	08:18	12 min	M1	1E-5	—	—
1991-10-30 18:11	18:16	18:30	19 min	M4.3	4E-5	S10W35	6891
1991-10-30 05:10	05:34	08:35	205 min	X2.5	2E-4	S08W25	6891
1991-10-29 20:15	20:42	20:53	38 min	M1.1	1E-5	S07W20	6891
1991-10-29 17:09	18:12	18:38	89 min	M4.7	5E-5	S10W23	6891
1991-10-29 08:53	09:00	09:07	14 min	M1.2	1E-5	—	—
1991-10-28 19:19	19:30	19:46	27 min	M1.3	1E-5	S11W05	6891
1991-10-28 16:11	16:49	17:49	98 min	M2.2	2E-5	S10W06	6891
1991-10-28 14:50	15:20	15:29	39 min	M1.3	1E-5	S11W00	6891
1991-10-28 14:23	14:30	14:42	19 min	M1.1	1E-5	S11W04	6891
1991-10-28 11:28	11:40	12:41	73 min	M2.1	2E-5	—	—
1991-10-28 06:36	06:42	06:55	19 min	M1.5	2E-5	S14E03	6891
1991-10-28 00:03	00:12	00:43	40 min	M1.1	1E-5	S11E07	6891
1991-10-27 11:54	12:01	12:23	29 min	M3.3	3E-5	S14E14	6891
1991-10-27 04:37	04:48	06:12	95 min	X6.1	6E-4	S13E15	6891
1991-10-27 01:06	01:12	01:55	49 min	X1.9	2E-4	S11E20	6891
1991-10-26 23:29	23:35	01:04	95 min	M2.3	2E-5	S14E19	6891
1991-10-26 17:46	19:47	21:43	237 min	X1.7	2E-4	S09E20	6891
1991-10-26 11:54	12:01	12:14	20 min	M1.2	1E-5	S14E26	6891
1991-10-25 23:05	23:15	02:50	225 min	M1.1	1E-5	S11E34	6891
1991-10-25 15:56	16:36	17:11	75 min	M1.4	1E-5	S11E35	6891
1991-10-25 09:41	10:24	11:58	137 min	M1.7	2E-5	S09E37	6891
1991-10-25 06:42	06:55	07:34	52 min	M1.3	1E-5	S20E41	6892
1991-10-24 21:24	21:41	21:51	27 min	M9.8	1E-4	S12E46	6891
1991-10-24 16:11	16:16	16:37	26 min	M3.2	3E-5	S15E51	6891
1991-10-24 15:54	15:57	16:09	15 min	M2.5	2E-5	S20E54	6892
1991-10-24 10:06	10:24	11:03	57 min	M1.2	1E-5	S12E53	6891
1991-10-24 08:44	08:48	09:03	19 min	M1.3	1E-5	S15E63	6891
1991-10-24 05:24	05:31	05:51	27 min	M1.2	1E-5	S12E56	6891
1991-10-24 01:31	01:40	01:56	25 min	X2.1	2E-4	S14E59	6891
1991-10-24 00:20	00:23	00:27	7 min	M1.4	1E-5	S20E62	6892
1991-10-23 23:35	23:55	00:20	45 min	M1.9	2E-5	S12E61	6891
1991-10-22 17:27	18:02	19:11	104 min	M1.9	2E-5	S09E69	6891
1991-10-22 05:27	05:44	07:13	106 min	M1.2	1E-5	S11E85	6891
1991-10-15 05:59	06:04	06:25	26 min	M1.4	1E-5	S23E30	6878
1991-10-15 00:27	00:31	00:44	17 min	M1.3	1E-5	S20E22	6878
1991-10-14 16:31	16:38	16:42	11 min	M6.6	7E-5	S24E34	6878
1991-10-14 10:36	10:42	10:49	13 min	M1	1E-5	—	—
1991-10-14 10:12	10:15	10:17	5 min	M1	1E-5	—	—
1991-10-14 09:52	09:57	10:03	11 min	M1.8	2E-5	—	—
1991-10-14 09:02	09:13	09:28	26 min	M1.1	1E-5	—	—
1991-10-14 02:16	02:22	02:32	16 min	M1.3	1E-5	N21E76	6879
1991-10-13 20:02	20:06	20:25	23 min	M1.6	2E-5	N22E80	6879

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