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Geomagnetic activity in October 1939
Mean Ap21.7No. 113 of 1138
G1+ days12
G3+ days5
Max Ap8913 Oct 1939
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 3 Oct 1939 | 6- | 38 | G2 |
| 4 Oct 1939 | 7+ | 51 | G3 |
| 6 Oct 1939 | 6+ | 32 | G2 |
| 7 Oct 1939 | 5- | 14 | G1 |
| 9 Oct 1939 | 7- | 32 | G3 |
| 13 Oct 1939 | 8o | 89 | G4 |
| 14 Oct 1939 | 7- | 74 | G3 |
| 15 Oct 1939 | 8o | 68 | G4 |
| 16 Oct 1939 | 6- | 35 | G2 |
| 17 Oct 1939 | 5+ | 36 | G1 |
| 18 Oct 1939 | 5- | 27 | G1 |
| 19 Oct 1939 | 5- | 24 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| October 1938 | 16.4 | 8 | 3 |
| October 1939 | 21.7 | 12 | 5 |
Dates and time slots are UTC. Kp is the 3-hourly planetary geomagnetic index (0–9); Ap is the daily average disturbance. G1–G5 follow the NOAA storm scale (Kp 5- and above counted as G1). Aurora visibility also depends on weather and location. The latest values are preliminary.
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About this page
Mean Ap 21.7 in October 1939, No. 113 of 1138 months since 1932; 12 days reached G1 or higher.