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Geomagnetic activity in May 1940
Mean Ap13.4No. 471 of 1138
G1+ days6
G3+ days1
Max Ap7824 May 1940
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 18 May 1940 | 6- | 34 | G2 |
| 22 May 1940 | 6- | 31 | G2 |
| 23 May 1940 | 5+ | 18 | G1 |
| 24 May 1940 | 8- | 78 | G4 |
| 26 May 1940 | 5+ | 24 | G1 |
| 27 May 1940 | 6- | 21 | G2 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| May 1939 | 21.4 | 16 | 2 |
| May 1940 | 13.4 | 6 | 1 |
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 13.4 in May 1940, No. 471 of 1138 months since 1932; 6 days reached G1 or higher.