Aurora & Space WeatherGeomagnetic activity in 1987
Mean Ap10.9
G1+56days
G3+1days
G50days
G1+ days by month
- January 1987
- February 1987
- March 1987
- April 1987
- May 1987
- June 1987
- July 1987
- August 1987
- September 1987
- October 1987
- November 1987
- December 1987
Nearby years (G1+ days)
159
140
139
83
71
56
59
123
104
141
107
Top 10 days by Ap
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 29 Jul 1987 | 7o | 52 | G3 |
| 25 Sep 1987 | 6o | 46 | G2 |
| 28 Oct 1987 | 6- | 44 | G2 |
| 30 Sep 1987 | 6o | 43 | G2 |
| 26 Aug 1987 | 6o | 40 | G2 |
| 11 Sep 1987 | 5+ | 40 | G1 |
| 25 Aug 1987 | 6o | 39 | G2 |
| 16 Dec 1987 | 6- | 39 | G2 |
| 10 Sep 1987 | 6+ | 38 | G2 |
| 3 Oct 1987 | 6o | 36 | G2 |
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
1987 had 56 G1+ storm days (No. 67 of 95 years) and 1 G3+ days.