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Geomagnetic activity in December 1938
Mean Ap11.4No. 636 of 1138
G1+ days7
G3+ days0
Max Ap3618 Dec 1938
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 2 Dec 1938 | 5o | 18 | G1 |
| 3 Dec 1938 | 5o | 28 | G1 |
| 10 Dec 1938 | 6- | 29 | G2 |
| 16 Dec 1938 | 5+ | 22 | G1 |
| 17 Dec 1938 | 5o | 30 | G1 |
| 18 Dec 1938 | 6- | 36 | G2 |
| 22 Dec 1938 | 5- | 22 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| December 1937 | 9.7 | 4 | 0 |
| December 1938 | 11.4 | 7 | 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 11.4 in December 1938, No. 636 of 1138 months since 1932; 7 days reached G1 or higher.