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
1981-07-26 03:55	04:06	04:14	19 min	M1.8	2E-5	S14E30	3234
1981-07-26 02:00	02:12	02:43	43 min	M2.8	3E-5	S12E31	3234
1981-07-25 10:28	10:50	12:20	112 min	M4.1	4E-5	S16W32	3234
1981-07-24 05:45	05:52	06:06	21 min	M1.4	1E-5	—	3234
1981-07-24 03:02	03:11	03:46	44 min	M1	1E-5	N16W30	3224
1981-07-23 21:06	21:26	21:50	44 min	M3.1	3E-5	S10E55	3234
1981-07-23 18:46	18:49	19:37	51 min	M2	2E-5	S09E50	3234
1981-07-23 16:52	17:46	21:30	278 min	M1.3	1E-5	S07E04	3221
1981-07-23 08:15	08:20	09:29	74 min	M1.1	1E-5	N15W20	3224
1981-07-22 19:54	19:55	22:15	141 min	M1	1E-5	N16W14	3224
1981-07-22 06:34	06:40	07:06	32 min	M2.1	2E-5	—	—
1981-07-22 02:16	02:22	02:30	14 min	M1.2	1E-5	—	—
1981-07-21 23:31	23:43	23:54	23 min	M1	1E-5	—	3221
1981-07-21 19:34	19:41	19:54	20 min	M1.4	1E-5	S13E77	3234
1981-07-21 17:08	17:10	17:21	13 min	M1	1E-5	S06E32	3221
1981-07-21 14:09	14:52	15:00	51 min	M1.1	1E-5	—	—
1981-07-21 11:15	11:15	11:34	19 min	M2.5	2E-5	S07E35	3221
1981-07-21 06:47	06:51	07:25	38 min	M2.1	2E-5	N17E16	3224
1981-07-21 01:21	02:03	02:45	84 min	M2.1	2E-5	N17E14	3224
1981-07-20 21:29	21:47	22:29	60 min	M2	2E-5	—	—
1981-07-20 15:29	15:32	16:30	61 min	M3.8	4E-5	S07W89	3219
1981-07-20 11:10	11:22	12:41	91 min	M5.4	5E-5	S26W75	3204
1981-07-19 03:32	03:34	04:37	65 min	X2.7	3E-4	S37W56	3204
1981-07-19 02:08	02:30	02:51	43 min	M9.1	9E-5	S08E66	3221
1981-07-18 23:53	00:00	01:23	90 min	M3.3	3E-5	S09E66	3221
1981-07-18 18:50	18:58	19:27	37 min	M4.1	4E-5	—	3221
1981-07-18 18:23	18:56	19:32	69 min	M1	1E-5	S08E71	3221
1981-07-18 13:32	14:01	14:35	63 min	M2.2	2E-5	S07E73	3221
1981-07-18 11:03	11:17	11:24	21 min	M1.1	1E-5	—	3221
1981-07-18 09:46	09:52	11:48	122 min	M1.5	2E-5	S10E80	3121
1981-07-18 05:03	05:08	05:56	53 min	M1.8	2E-5	S08E77	3221
1981-07-17 15:03	15:03	16:02	59 min	M1.6	2E-5	S08W41	3203
1981-07-17 10:09	10:30	11:26	77 min	M3.7	4E-5	S08E37	3203
1981-07-17 09:23	09:27	09:33	10 min	M1.2	1E-5	—	—
1981-07-17 05:53	06:09	06:30	37 min	X1.7	2E-4	—	3221
1981-07-16 23:48	23:53	01:00	72 min	M4.1	4E-5	S09W30	3203
1981-07-16 17:34	17:46	18:28	54 min	M1.9	2E-5	S09W25	3203
1981-07-16 14:35	14:42	15:18	43 min	M1.4	1E-5	S28W24	3204
1981-07-16 14:07	14:12	14:53	46 min	M1.4	1E-5	S08W26	3203
1981-07-16 08:15	08:20	08:37	22 min	M3.4	3E-5	S05W25	3203
1981-07-16 04:34	04:42	05:46	72 min	M1.8	2E-5	S09W19	3203
1981-07-15 14:42	14:47	16:00	78 min	M2.5	2E-5	S08W12	3203
1981-07-15 06:01	06:18	07:09	68 min	M5.1	5E-5	S10W07	3203
1981-07-15 01:54	02:02	02:45	51 min	M1.9	2E-5	S10W03	3203
1981-07-12 10:08	10:09	10:33	25 min	M1.1	1E-5	S28E38	3204
1981-07-12 00:35	01:16	01:54	79 min	M1.1	1E-5	S28E34	3204
1981-07-10 13:18	13:19	13:35	17 min	M1.8	2E-5	S09E61	3203
1981-07-09 10:59	11:10	11:29	30 min	M2.1	2E-5	—	3203
1981-07-07 00:30	00:52	01:08	38 min	M1.1	1E-5	—	—
1981-07-03 17:07	17:08	17:57	50 min	M1.1	1E-5	N12W76	3188

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