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Geomagnetic activity in May 1987
Mean Ap7.7No. 963 of 1138
G1+ days3
G3+ days0
Max Ap2525 May 1987
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 24 May 1987 | 5o | 20 | G1 |
| 25 May 1987 | 6- | 25 | G2 |
| 29 May 1987 | 5- | 21 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| May 1986 | 11.6 | 5 | 3 |
| May 1987 | 7.7 | 3 | 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 7.7 in May 1987, No. 963 of 1138 months since 1932; 3 days reached G1 or higher.