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Geomagnetic activity in July 1987
Mean Ap10.8No. 685 of 1138
G1+ days4
G3+ days1
Max Ap5229 Jul 1987
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 15 Jul 1987 | 5- | 24 | G1 |
| 28 Jul 1987 | 5+ | 26 | G1 |
| 29 Jul 1987 | 7o | 52 | G3 |
| 31 Jul 1987 | 5o | 14 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| July 1986 | 8.2 | 3 | 0 |
| July 1987 | 10.8 | 4 | 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 10.8 in July 1987, No. 685 of 1138 months since 1932; 4 days reached G1 or higher.