Geomagnetic Storms of 1973
62 geomagnetic storms of G1 or more began in 1973: 31 G1, 21 G2, 6 G3, 4 G4, 0 G5. The strongest began April 1, 1973 and reached Kp 8+, rank 100 of every storm since 1932.
By month
Every storm of 1973
Times are UT, when the first block at Kp 5 or more began.
| Began (UTC) | Level | Peak Kp | Hours | Highest daily Ap |
|---|---|---|---|---|
| Jan 5, 21:00 | G1 Minor | 5 | 3 | 21 |
| Jan 8, 15:00 | G1 Minor | 5 | 3 | 15 |
| Jan 10, 18:00 | G1 Minor | 5 | 3 | 28 |
| Jan 12, 12:00 | G1 Minor | 5 | 3 | 25 |
| Jan 20, 00:00 | G2 Moderate | 6 | 6 | 29 |
| Jan 21, 06:00 | G1 Minor | 5 | 3 | 23 |
| Jan 25, 09:00 | G1 Minor | 5 | 3 | 20 |
| Jan 27, 03:00 | G1 Minor | 5 | 3 | 33 |
| Jan 27, 18:00 | G2 Moderate | 6- | 12 | 33 |
| Feb 21, 15:00 | G3 Strong | 7+ | 12 | 49 |
| Feb 22, 18:00 | G2 Moderate | 6+ | 54 | 54 |
| Feb 25, 15:00 | G1 Minor | 5 | 12 | 34 |
| Feb 26, 21:00 | G2 Moderate | 6 | 30 | 44 |
| Mar 1, 15:00 | G1 Minor | 5+ | 30 | 40 |
| Mar 6, 12:00 | G2 Moderate | 6- | 6 | 28 |
| Mar 18, 21:00 | G3 Strong | 7 | 171 | 82 |
| Mar 26, 18:00 | G2 Moderate | 6+ | 3 | 32 |
| Mar 31, 15:00 | G2 Moderate | 6 | 9 | 33 |
| Apr 1, 12:00 | G4 Severe | 8+ | 42 | 91 |
| Apr 13, 09:00 | G4 Severe | 8- | 33 | 57 |
| Apr 16, 06:00 | G2 Moderate | 6+ | 60 | 60 |
| Apr 19, 18:00 | G2 Moderate | 6 | 72 | 46 |
| Apr 26, 18:00 | G2 Moderate | 6- | 3 | 28 |
| Apr 28, 12:00 | G2 Moderate | 6 | 33 | 59 |
| May 13, 21:00 | G4 Severe | 8- | 24 | 81 |
| May 15, 18:00 | G1 Minor | 5+ | 9 | 37 |
| May 16, 21:00 | G2 Moderate | 6 | 3 | 33 |
| May 21, 03:00 | G3 Strong | 7 | 9 | 48 |
| May 22, 03:00 | G1 Minor | 5 | 3 | 21 |
| Jun 10, 18:00 | G2 Moderate | 6+ | 6 | 33 |
| Jun 11, 12:00 | G1 Minor | 5+ | 6 | 34 |
| Jun 18, 00:00 | G1 Minor | 5+ | 3 | 30 |
| Jun 19, 00:00 | G1 Minor | 5+ | 21 | 38 |
| Jun 24, 12:00 | G1 Minor | 5 | 9 | 34 |
| Jun 28, 21:00 | G2 Moderate | 6+ | 18 | 41 |
| Jul 15, 18:00 | G1 Minor | 5+ | 9 | 32 |
| Jul 26, 12:00 | G1 Minor | 5+ | 12 | 36 |
| Jul 27, 18:00 | G1 Minor | 5 | 3 | 29 |
| Jul 31, 03:00 | G1 Minor | 5 | 3 | 26 |
| Aug 24, 00:00 | G2 Moderate | 6 | 15 | 46 |
| Aug 25, 06:00 | G1 Minor | 5 | 3 | 29 |
| Aug 27, 15:00 | G1 Minor | 5 | 3 | 26 |
| Aug 28, 15:00 | G1 Minor | 5 | 3 | 28 |
| Sep 9, 18:00 | G4 Severe | 8- | 6 | 44 |
| Sep 10, 18:00 | G2 Moderate | 6 | 3 | 27 |
| Sep 22, 21:00 | G3 Strong | 7 | 24 | 63 |
| Sep 25, 18:00 | G2 Moderate | 6- | 18 | 27 |
| Oct 2, 06:00 | G1 Minor | 5 | 3 | 31 |
| Oct 3, 00:00 | G3 Strong | 7+ | 9 | 48 |
| Oct 10, 03:00 | G1 Minor | 5 | 3 | 21 |
| Oct 16, 06:00 | G1 Minor | 5+ | 15 | 30 |
| Oct 18, 12:00 | G1 Minor | 5 | 3 | 22 |
| Oct 21, 12:00 | G1 Minor | 5+ | 12 | 37 |
| Oct 28, 21:00 | G3 Strong | 7 | 30 | 86 |
| Oct 31, 03:00 | G1 Minor | 5 | 3 | 19 |
| Nov 4, 21:00 | G1 Minor | 5 | 3 | 18 |
| Nov 7, 06:00 | G2 Moderate | 6- | 15 | 28 |
| Nov 17, 00:00 | G1 Minor | 5 | 3 | 17 |
| Nov 21, 18:00 | G2 Moderate | 6- | 3 | 23 |
| Nov 24, 15:00 | G2 Moderate | 6- | 18 | 42 |
| Dec 4, 21:00 | G2 Moderate | 6 | 6 | 29 |
| Dec 20, 18:00 | G1 Minor | 5+ | 33 | 34 |
More
Sources
Kp and ap from GFZ Helmholtz Centre for Geosciences, Geomagnetic Observatory Niemegk, licensed CC BY 4.0: Matzka, J., Stolle, C., Yamazaki, Y., Bronkalla, O. and Morschhauser, A., 2021, The geomagnetic Kp index and derived indices of geomagnetic activity, Space Weather, doi:10.1029/2020SW002641; data doi:10.5880/Kp.0001. Storms, levels and aurora reach worked out by WeatherOverTime from those values and NOAA’s space weather scales. Definitive through August 31, 2026; later values are preliminary. Rebuilt 2026-09-24.