Geomagnetic Storms of 1941
63 geomagnetic storms of G1 or more began in 1941: 32 G1, 20 G2, 4 G3, 4 G4, 3 G5. The strongest began September 18, 1941 and reached Kp 9, rank 4 of every storm since 1932.
By month
Every storm of 1941
Times are UT, when the first block at Kp 5 or more began.
| Began (UTC) | Level | Peak Kp | Hours | Highest daily Ap |
|---|---|---|---|---|
| Jan 6, 03:00 | G1 Minor | 5 | 6 | 20 |
| Jan 17, 00:00 | G2 Moderate | 6- | 24 | 42 |
| Jan 18, 18:00 | G1 Minor | 5+ | 3 | 32 |
| Jan 24, 12:00 | G2 Moderate | 6- | 6 | 34 |
| Jan 26, 00:00 | G1 Minor | 5 | 3 | 23 |
| Feb 7, 03:00 | G1 Minor | 5+ | 3 | 30 |
| Feb 13, 12:00 | G1 Minor | 5 | 3 | 27 |
| Feb 14, 09:00 | G1 Minor | 5 | 3 | 26 |
| Feb 15, 03:00 | G1 Minor | 5+ | 3 | 28 |
| Feb 21, 12:00 | G2 Moderate | 6- | 33 | 41 |
| Feb 23, 18:00 | G2 Moderate | 6- | 6 | 37 |
| Feb 24, 15:00 | G1 Minor | 5 | 3 | 23 |
| Mar 1, 03:00 | G5 Extreme | 9 | 24 | 207 |
| Mar 3, 15:00 | G1 Minor | 5+ | 3 | 27 |
| Mar 4, 09:00 | G1 Minor | 5+ | 39 | 40 |
| Mar 11, 21:00 | G1 Minor | 5 | 3 | 15 |
| Mar 14, 00:00 | G3 Strong | 7 | 24 | 79 |
| Mar 19, 12:00 | G1 Minor | 5+ | 3 | 24 |
| Mar 20, 15:00 | G1 Minor | 5+ | 3 | 33 |
| Mar 21, 18:00 | G2 Moderate | 6 | 27 | 40 |
| Mar 23, 21:00 | G1 Minor | 5 | 3 | 21 |
| Mar 28, 09:00 | G2 Moderate | 6+ | 15 | 59 |
| Mar 29, 18:00 | G4 Severe | 8- | 45 | 85 |
| Apr 10, 15:00 | G1 Minor | 5 | 18 | 27 |
| Apr 12, 03:00 | G1 Minor | 5 | 3 | 19 |
| Apr 18, 21:00 | G2 Moderate | 6+ | 12 | 39 |
| Apr 24, 06:00 | G3 Strong | 7- | 27 | 63 |
| Apr 26, 09:00 | G1 Minor | 5+ | 3 | 18 |
| Apr 29, 00:00 | G1 Minor | 5+ | 3 | 14 |
| May 17, 03:00 | G1 Minor | 5+ | 6 | 25 |
| May 21, 21:00 | G1 Minor | 5 | 6 | 31 |
| May 22, 18:00 | G1 Minor | 5 | 3 | 31 |
| May 23, 21:00 | G1 Minor | 5 | 3 | 23 |
| Jun 10, 12:00 | G2 Moderate | 6 | 15 | 31 |
| Jun 13, 06:00 | G2 Moderate | 6 | 18 | 39 |
| Jun 17, 18:00 | G1 Minor | 5+ | 3 | 18 |
| Jun 20, 06:00 | G1 Minor | 5+ | 3 | 22 |
| Jul 4, 18:00 | G5 Extreme | 9 | 30 | 222 |
| Jul 6, 12:00 | G3 Strong | 7 | 21 | 54 |
| Jul 10, 21:00 | G1 Minor | 5 | 3 | 21 |
| Jul 21, 03:00 | G2 Moderate | 6 | 9 | 38 |
| Aug 2, 09:00 | G1 Minor | 5+ | 9 | 37 |
| Aug 4, 00:00 | G4 Severe | 8+ | 27 | 110 |
| Aug 6, 21:00 | G2 Moderate | 6- | 3 | 23 |
| Aug 27, 00:00 | G2 Moderate | 6 | 36 | 59 |
| Aug 29, 09:00 | G1 Minor | 5+ | 3 | 32 |
| Aug 30, 00:00 | G1 Minor | 5+ | 6 | 25 |
| Sep 7, 12:00 | G1 Minor | 5 | 3 | 20 |
| Sep 13, 12:00 | G2 Moderate | 6- | 6 | 24 |
| Sep 15, 18:00 | G2 Moderate | 6- | 9 | 27 |
| Sep 18, 03:00 | G5 Extreme | 9 | 60 | 232 |
| Sep 21, 03:00 | G2 Moderate | 6 | 15 | 30 |
| Sep 24, 21:00 | G2 Moderate | 6- | 6 | 27 |
| Oct 11, 18:00 | G3 Strong | 7- | 9 | 42 |
| Oct 22, 15:00 | G2 Moderate | 6+ | 9 | 33 |
| Oct 31, 03:00 | G2 Moderate | 6- | 3 | 47 |
| Oct 31, 18:00 | G4 Severe | 8- | 24 | 79 |
| Nov 6, 06:00 | G1 Minor | 5+ | 15 | 43 |
| Nov 17, 15:00 | G1 Minor | 5 | 3 | 34 |
| Nov 19, 00:00 | G2 Moderate | 6- | 3 | 19 |
| Nov 28, 03:00 | G2 Moderate | 6+ | 18 | 53 |
| Dec 1, 06:00 | G4 Severe | 8- | 24 | 83 |
| Dec 16, 03:00 | G1 Minor | 5 | 3 | 13 |
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.