Aurora & Space WeatherHome › Geomagnetic history › 1987
Geomagnetic activity in August 1987
Mean Ap13.4No. 473 of 1138
G1+ days8
G3+ days0
Max Ap4026 Aug 1987
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 3 Aug 1987 | 5- | 12 | G1 |
| 13 Aug 1987 | 6- | 23 | G2 |
| 25 Aug 1987 | 6o | 39 | G2 |
| 26 Aug 1987 | 6o | 40 | G2 |
| 27 Aug 1987 | 5- | 21 | G1 |
| 28 Aug 1987 | 5- | 15 | G1 |
| 30 Aug 1987 | 5- | 14 | G1 |
| 31 Aug 1987 | 6- | 34 | G2 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| August 1986 | 12.4 | 10 | 0 |
| August 1987 | 13.4 | 8 | 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 13.4 in August 1987, No. 473 of 1138 months since 1932; 8 days reached G1 or higher.