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

C3.3

2026-10-23 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) · 10/23/26

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

Catalogued flares

94,026

1975 → 2026-10-23

GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/23/26

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) · 10/23/26

Latest catalogued flare

C3.3

2026-10-23 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) · 10/23/26

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) · 10/23/26

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) · 10/23/26 GOES X-ray flare lists (NOAA SWPC/NGDC events, yearly compilations by NASA GSFC) · U.S. Government work, public domain (NOAA/NASA) · 10/23/26

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) · 10/23/26

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) · 10/23/26

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Start (UTC)	Peak	End	Duration	Class	Peak flux (W/m²)	Position	Active region
2025-06-15 15:45	16:07	16:25	40 min	M8.4	8E-5	—	14114
2025-06-15 08:32	08:47	08:53	21 min	M1.9	2E-5	—	14105
2025-06-15 05:45	05:56	06:02	17 min	M2.2	2E-5	S14W67	14105
2025-06-14 20:51	21:01	21:09	18 min	M6.8	7E-5	—	14105
2025-06-14 15:52	16:04	16:13	21 min	M1	1E-5	—	14105
2025-06-13 18:49	19:10	19:21	32 min	M1.2	1E-5	—	14105
2025-06-04 21:06	21:28	21:39	33 min	M1.1	1E-5	—	14100
2025-06-03 10:52	11:03	11:12	20 min	M1.4	1E-5	—	14105
2025-06-02 19:35	19:42	19:46	11 min	M1.1	1E-5	—	14100
2025-06-02 08:59	09:18	09:39	40 min	M3.3	3E-5	—	14100
2025-05-31 13:36	13:49	13:57	21 min	M2.9	3E-5	N06E03	14100
2025-05-31 06:08	06:18	06:23	15 min	M4.5	4E-5	—	14100
2025-05-31 03:12	03:18	03:20	8 min	M2.4	2E-5	—	14100
2025-05-31 01:49	01:56	02:04	15 min	M1	1E-5	—	14100
2025-05-30 16:22	16:39	16:54	32 min	M1.6	2E-5	—	14104
2025-05-30 03:56	04:13	04:19	23 min	M3.4	3E-5	N06E55	14100
2025-05-26 11:27	11:37	11:44	17 min	M1.4	1E-5	N11E70	14100
2025-05-26 10:50	11:06	11:15	25 min	M2.9	3E-5	S05W67	14098
2025-05-25 14:18	14:30	14:36	18 min	M8.9	9E-5	—	14098
2025-05-25 08:05	08:18	08:25	20 min	M3.4	3E-5	S05W50	14098
2025-05-25 04:27	04:35	04:38	11 min	M1.7	2E-5	—	14098
2025-05-24 23:46	23:52	23:57	11 min	X1.1	1E-4	—	14098
2025-05-24 18:14	18:23	18:29	15 min	M2.1	2E-5	—	14098
2025-05-20 22:01	22:08	22:10	9 min	M1.2	1E-5	N18W21	14087
2025-05-19 06:13	06:21	06:26	13 min	M3.2	3E-5	—	—
2025-05-15 15:08	15:21	15:27	19 min	M2.1	2E-5	—	14087
2025-05-14 15:59	16:11	16:18	19 min	M4.7	5E-5	—	14087
2025-05-14 09:04	09:19	09:31	27 min	M7.7	8E-5	—	14087
2025-05-14 06:04	06:25	06:31	27 min	X2.7	3E-4	N15E68	14087
2025-05-14 05:36	05:45	05:51	15 min	M1.2	1E-5	—	14087
2025-05-14 01:05	01:25	01:35	30 min	M5.3	5E-5	—	14087
2025-05-13 13:25	13:38	13:44	19 min	X1.2	1E-4	—	14086
2025-04-30 05:41	05:51	05:56	15 min	M2	2E-5	—	14079
2025-04-29 08:49	08:57	09:09	20 min	M1.6	2E-5	N15W51	14078
2025-04-29 07:45	08:02	08:12	27 min	M1.3	1E-5	N15W50	14078
2025-04-29 03:10	03:13	03:17	7 min	M1.7	2E-5	—	14079
2025-04-22 06:38	08:49	09:34	176 min	M1.3	1E-5	—	14063
2025-04-21 16:24	16:37	16:41	17 min	M1.9	2E-5	N01W14	14062
2025-04-20 09:37	10:11	10:59	82 min	M1	1E-5	—	—
2025-04-15 15:57	16:13	16:27	30 min	M1.3	1E-5	—	14055
2025-04-15 08:04	08:20	08:28	24 min	M1.5	2E-5	—	—
2025-04-14 04:36	04:50	04:58	22 min	M4.2	4E-5	—	14055
2025-04-14 04:00	04:05	04:11	11 min	M1.4	1E-5	—	14055
2025-04-13 16:38	16:51	17:00	22 min	M3.2	3E-5	—	14055
2025-04-13 13:28	13:42	13:56	28 min	M1.2	1E-5	—	14055
2025-04-13 08:03	08:07	08:10	7 min	M1.2	1E-5	—	14055
2025-04-13 07:43	07:55	08:03	20 min	M1.4	1E-5	—	14055
2025-04-13 04:38	04:52	05:21	43 min	M1	1E-5	N07W67	14055
2025-04-13 02:48	02:52	02:54	6 min	M2.3	2E-5	—	14055
2025-04-13 02:25	02:28	02:31	6 min	M1.1	1E-5	—	14055

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 23, 2026 · SHA-256 9c4ca1a2c018…
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