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Geomagnetic activity in April 1957
Mean Ap21.5No. 117 of 1138
G1+ days14
G3+ days3
Max Ap6019 Apr 1957
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 3 Apr 1957 | 5o | 20 | G1 |
| 5 Apr 1957 | 6- | 37 | G2 |
| 6 Apr 1957 | 6- | 27 | G2 |
| 9 Apr 1957 | 5- | 25 | G1 |
| 10 Apr 1957 | 7- | 58 | G3 |
| 11 Apr 1957 | 5- | 17 | G1 |
| 15 Apr 1957 | 6- | 18 | G2 |
| 17 Apr 1957 | 8- | 55 | G4 |
| 18 Apr 1957 | 6+ | 42 | G2 |
| 19 Apr 1957 | 7- | 60 | G3 |
| 24 Apr 1957 | 5- | 27 | G1 |
| 26 Apr 1957 | 5- | 23 | G1 |
| 27 Apr 1957 | 5o | 20 | G1 |
| 28 Apr 1957 | 5- | 18 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| April 1956 | 27.4 | 11 | 6 |
| April 1957 | 21.5 | 14 | 3 |
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 21.5 in April 1957, No. 117 of 1138 months since 1932; 14 days reached G1 or higher.