Geomagnetic Storms of 1933
33 geomagnetic storms of G1 or more began in 1933: 21 G1, 9 G2, 2 G3, 1 G4, 0 G5. The strongest began May 1, 1933 and reached Kp 8-, rank 242 of every storm since 1932.
By month
Every storm of 1933
Times are UT, when the first block at Kp 5 or more began.
| Began (UTC) | Level | Peak Kp | Hours | Highest daily Ap |
|---|---|---|---|---|
| Jan 20, 03:00 | G1 Minor | 5 | 3 | 13 |
| Jan 24, 00:00 | G1 Minor | 5 | 3 | 15 |
| Jan 27, 21:00 | G1 Minor | 5 | 3 | 25 |
| Feb 19, 21:00 | G2 Moderate | 6- | 6 | 29 |
| Feb 21, 03:00 | G1 Minor | 5+ | 24 | 35 |
| Feb 23, 15:00 | G1 Minor | 5 | 3 | 30 |
| Feb 24, 21:00 | G1 Minor | 5+ | 3 | 32 |
| Mar 18, 03:00 | G1 Minor | 5 | 3 | 32 |
| Mar 18, 21:00 | G2 Moderate | 6+ | 6 | 32 |
| Mar 19, 18:00 | G2 Moderate | 6 | 9 | 37 |
| Mar 20, 18:00 | G1 Minor | 5+ | 3 | 37 |
| Mar 22, 00:00 | G1 Minor | 5+ | 3 | 27 |
| Mar 23, 03:00 | G1 Minor | 5+ | 27 | 31 |
| Apr 17, 12:00 | G2 Moderate | 6- | 3 | 30 |
| Apr 19, 21:00 | G1 Minor | 5 | 3 | 26 |
| Apr 21, 21:00 | G2 Moderate | 6- | 3 | 22 |
| Apr 30, 21:00 | G1 Minor | 5+ | 3 | 18 |
| May 1, 12:00 | G4 Severe | 8- | 15 | 82 |
| May 4, 18:00 | G1 Minor | 5 | 3 | 16 |
| May 31, 12:00 | G1 Minor | 5 | 3 | 22 |
| Jun 1, 03:00 | G1 Minor | 5 | 3 | 21 |
| Jun 13, 00:00 | G1 Minor | 5+ | 6 | 36 |
| Jun 13, 21:00 | G2 Moderate | 6- | 6 | 36 |
| Jul 9, 09:00 | G1 Minor | 5 | 3 | 19 |
| Jul 23, 12:00 | G1 Minor | 5 | 3 | 19 |
| Jul 24, 06:00 | G1 Minor | 5+ | 12 | 29 |
| Aug 5, 12:00 | G3 Strong | 7- | 15 | 36 |
| Aug 13, 18:00 | G2 Moderate | 6- | 3 | 22 |
| Sep 9, 03:00 | G3 Strong | 7- | 9 | 54 |
| Sep 13, 15:00 | G2 Moderate | 6 | 6 | 26 |
| Sep 15, 03:00 | G2 Moderate | 6 | 3 | 27 |
| Oct 12, 00:00 | G1 Minor | 5+ | 6 | 19 |
| Nov 6, 12:00 | G1 Minor | 5 | 3 | 25 |
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 2026-09-26.