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
1984-11-10 03:32	03:39	04:17	45 min	M2.1	2E-5	N17E14	4592
1984-08-18 20:39	21:05	21:27	48 min	M1.1	1E-5	—	—
1984-07-03 22:51	00:46	02:13	202 min	M1.4	1E-5	S08E68	4532
1984-05-31 09:29	09:42	09:56	27 min	M1.7	2E-5	—	4492
1984-05-25 06:41	06:46	07:28	47 min	M1.7	2E-5	S07W07	4492
1984-05-23 02:54	03:12	03:31	37 min	M1.8	2E-5	S08E24	4492
1984-05-22 12:53	13:01	14:16	83 min	M6.3	6E-5	S09E24	4492
1984-05-22 04:26	04:38	04:49	23 min	M1.4	1E-5	—	4492
1984-05-21 17:36	18:27	19:31	115 min	X2.7	3E-4	S06E40	4492
1984-05-21 00:18	01:26	01:57	99 min	M5.7	6E-5	—	—
1984-05-20 20:18	20:41	22:37	139 min	X10	1E-3	S09E52	4492
1984-05-20 04:16	04:20	04:25	9 min	M1.2	1E-5	—	4492
1984-05-20 03:29	03:43	04:01	32 min	M5.4	5E-5	—	4492
1984-05-20 02:02	02:08	02:18	16 min	M1	1E-5	—	4492
1984-05-20 00:46	01:03	01:26	40 min	M4.6	5E-5	S08E64	4492
1984-05-19 23:26	23:27	00:03	37 min	M2.9	3E-5	S10E65	4492
1984-05-19 19:51	20:00	20:00	9 min	X4.1	4E-4	S07E67	4492
1984-05-19 05:49	05:50	05:52	3 min	M1	1E-5	N06W86	4481
1984-05-18 11:00	11:13	11:27	27 min	M1.5	2E-5	—	—
1984-05-18 00:24	00:28	00:47	23 min	M1.7	2E-5	—	4492
1984-05-12 03:32	03:42	04:19	47 min	M1.3	1E-5	N02W02	4481
1984-05-11 08:47	08:48	08:52	5 min	M1.1	1E-5	N06E21	4481
1984-05-11 05:28	05:32	05:51	23 min	M1.8	2E-5	N03E12	4481
1984-05-10 15:20	15:51	16:26	66 min	M4.7	5E-5	N03E21	4481
1984-05-05 16:08	16:27	16:49	41 min	M7.5	8E-5	—	4474
1984-05-05 09:16	10:07	10:55	99 min	M7.1	7E-5	—	4481
1984-05-04 14:04	14:17	14:59	55 min	M1.3	1E-5	—	4474
1984-05-02 17:15	17:33	19:44	149 min	M3	3E-5	S07W60	4474
1984-04-30 22:21	23:30	01:07	166 min	M4	4E-5	S14W32	4474
1984-04-30 09:34	09:59	10:53	79 min	M2.3	2E-5	S11W31	4474
1984-04-30 04:21	04:31	04:44	23 min	M1	1E-5	—	4474
1984-04-30 03:41	04:03	04:20	39 min	M1.1	1E-5	—	4474
1984-04-29 12:13	12:23	13:00	47 min	M1	1E-5	S12W24	4474
1984-04-29 03:42	04:56	06:32	170 min	M1.5	2E-5	S17E02	4474
1984-04-27 15:51	15:53	17:01	70 min	M1	1E-5	S12E02	4474
1984-04-27 14:49	15:09	15:10	21 min	M1.8	2E-5	—	4474
1984-04-27 11:48	12:11	16:35	287 min	M2.5	2E-5	S14E16	4474
1984-04-27 03:32	03:41	03:46	14 min	M1.4	1E-5	—	4474
1984-04-26 15:22	15:26	15:44	22 min	M2.8	3E-5	S09E31	4474
1984-04-26 08:59	10:53	12:27	208 min	M2.7	3E-5	S11E23	4474
1984-04-26 06:53	07:06	07:24	31 min	M2.5	2E-5	S09E34	4474
1984-04-26 04:54	04:58	05:10	16 min	M1.8	2E-5	S10E38	4474
1984-04-25 12:58	13:01	13:12	14 min	M1.7	2E-5	S10E45	4474
1984-04-24 21:56	22:01	23:40	104 min	X13	1E-3	S12E43	4474
1984-04-24 18:15	18:20	18:30	15 min	M1.1	1E-5	S11E56	4474
1984-04-24 15:24	15:28	15:34	10 min	M1.5	2E-5	—	4474
1984-04-24 00:59	02:20	03:24	145 min	X1	1E-4	S10E57	4474
1984-04-23 13:55	14:40	14:46	51 min	M7.2	7E-5	—	4474
1984-04-23 03:07	03:15	04:29	82 min	M1.8	2E-5	S11E62	4474
1984-04-22 23:48	00:01	00:17	29 min	M3.6	4E-5	—	4474

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