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 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) · 10/25/26 Current · provisional

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 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) · 10/25/26 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) · 10/25/26

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Start (UTC)	Peak	End	Duration	Class	Peak flux (W/m²)	Position	Active region
2003-10-23 17:50	18:04	18:14	24 min	X1.1	1E-4	S17E84	10486
2003-10-23 08:49	08:53	08:55	6 min	M2.7	3E-5	—	10484
2003-10-23 06:19	06:35	06:49	30 min	X5.4	5E-4	S21E88	10486
2003-10-23 05:02	05:08	05:10	8 min	M3.2	3E-5	N04E13	10484
2003-10-23 00:35	00:41	00:44	9 min	M2.4	2E-5	N03E15	10484
2003-10-22 19:56	20:04	20:17	21 min	M2.1	2E-5	—	10486
2003-10-22 17:47	18:07	18:28	41 min	M9.9	1E-4	S18E78	10486
2003-10-22 13:57	14:01	14:04	7 min	M1.2	1E-5	N03E17	10484
2003-10-22 13:06	13:11	13:13	7 min	M1.4	1E-5	N05E22	10484
2003-10-22 07:37	07:56	07:59	22 min	M1.7	2E-5	—	10486
2003-10-22 06:30	06:44	06:53	23 min	M1.7	2E-5	—	10486
2003-10-22 01:28	01:51	03:21	113 min	M3.7	4E-5	N07E25	10486
2003-10-21 17:22	21:30	01:05	463 min	M2.4	2E-5	—	—
2003-10-21 06:21	06:27	06:31	10 min	M1	1E-5	N03E34	10484
2003-10-20 04:45	05:22	05:43	58 min	M1.9	2E-5	—	10484
2003-10-19 17:21	17:26	17:30	9 min	M1	1E-5	N05E54	10484
2003-10-19 14:29	14:50	15:04	35 min	X1.1	1E-4	N08E58	10484
2003-10-19 04:08	04:26	04:41	33 min	M1.9	2E-5	N06E62	10484
2003-10-04 13:42	13:47	13:49	7 min	M1	1E-5	S10E29	10471
2003-10-01 02:44	02:51	02:59	15 min	M1.4	1E-5	N05W57	10464
2003-09-16 19:30	20:24	21:31	121 min	M1.3	1E-5	—	—
2003-08-19 07:45	08:06	08:25	40 min	M2.7	3E-5	S10W57	10431
2003-08-19 05:38	05:59	06:01	23 min	M2	2E-5	S12W63	10431
2003-08-05 10:43	10:49	10:51	8 min	M1.7	2E-5	S16E33	10424
2003-08-02 21:41	21:54	22:02	21 min	M1.3	1E-5	S17E63	10424
2003-07-30 02:04	02:10	02:12	8 min	M2.5	2E-5	N14W55	10422
2003-07-28 23:28	23:39	23:43	15 min	M1.3	1E-5	—	10421
2003-07-12 16:57	17:06	17:13	16 min	M1.4	1E-5	N16E79	—
2003-07-10 11:54	12:12	12:23	29 min	M3.6	4E-5	—	10397
2003-07-09 19:59	20:38	20:45	46 min	M2	2E-5	—	10397
2003-07-05 22:06	22:32	22:40	34 min	M2.3	2E-5	N04E18	10400
2003-07-02 05:06	05:28	05:46	40 min	M3	3E-5	N13E25	10397
2003-06-17 20:27	20:55	21:12	45 min	M6.8	7E-5	—	10386
2003-06-16 09:52	10:00	10:04	12 min	M1.7	2E-5	S12E83	10386
2003-06-16 00:44	00:48	00:51	7 min	M1	1E-5	—	10386
2003-06-15 21:25	21:56	22:25	60 min	X1.3	1E-4	S07E80	10386
2003-06-14 03:07	04:09	04:57	110 min	M1.5	2E-5	—	—
2003-06-13 04:28	04:45	05:19	51 min	M1.8	2E-5	N14W81	10375
2003-06-13 02:31	02:37	02:43	12 min	M1.7	2E-5	N15W78	10375
2003-06-12 23:54	00:04	00:13	19 min	M3.1	3E-5	—	—
2003-06-12 19:22	19:27	19:31	9 min	M2.6	3E-5	—	10375
2003-06-12 15:06	15:12	15:16	10 min	M1.1	1E-5	N14W73	10375
2003-06-12 11:58	12:03	12:09	11 min	M1	1E-5	N10W65	10375
2003-06-11 23:04	23:30	23:52	48 min	M7.3	7E-5	N15W65	10375
2003-06-11 19:41	19:51	20:10	29 min	M2.9	3E-5	N15W63	10375
2003-06-11 18:01	18:14	18:27	26 min	X1.6	2E-4	N14W57	10375
2003-06-11 15:27	15:43	16:00	33 min	M1.8	2E-5	S16E23	10380
2003-06-11 14:21	14:36	14:50	29 min	M4.5	4E-5	N12W59	10375
2003-06-11 12:37	13:27	13:47	70 min	M3.7	4E-5	N10W61	10375
2003-06-11 11:09	11:21	11:37	28 min	M2.7	3E-5	N11W61	10375

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