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Geomagnetic activity in December 1940
Mean Ap14.6No. 380 of 1138
G1+ days8
G3+ days0
Max Ap4420 Dec 1940
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 2 Dec 1940 | 5o | 25 | G1 |
| 20 Dec 1940 | 6o | 44 | G2 |
| 21 Dec 1940 | 6- | 32 | G2 |
| 22 Dec 1940 | 5o | 22 | G1 |
| 28 Dec 1940 | 5- | 14 | G1 |
| 29 Dec 1940 | 5- | 21 | G1 |
| 30 Dec 1940 | 6+ | 34 | G2 |
| 31 Dec 1940 | 5- | 22 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| December 1939 | 11.0 | 5 | 0 |
| December 1940 | 14.6 | 8 | 0 |
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.
About this page
Mean Ap 14.6 in December 1940, No. 380 of 1138 months since 1932; 8 days reached G1 or higher.