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Geomagnetic storm on 9 May 1978 (G4)
Max Kp8-G4
Ap85No. 7 in 1978
Consecutive G1+ days3
Ap rank257since 1932
Kp by 3-hour slot (UTC)
5o
5o
8-
6+
7o
7-
5o
3+
The days around it
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 6 May 1978 | 3- | 5 | – |
| 7 May 1978 | 3- | 7 | – |
| 8 May 1978 | 4+ | 16 | – |
| 9 May 1978 | 8- | 85 | G4 |
| 10 May 1978 | 5- | 10 | G1 |
| 11 May 1978 | 6o | 30 | G2 |
| 12 May 1978 | 4- | 18 | – |
Highest-Ap days of 1978
124
109
96
94
89
88
85
83
82
80
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
Max Kp 8-, Ap 85: No. 257 of 34,615 days since 1932 by Ap.