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Geomagnetic activity in September 1981
Mean Ap12.5No. 548 of 1138
G1+ days4
G3+ days0
Max Ap3819 Sep 1981
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 18 Sep 1981 | 6- | 18 | G2 |
| 19 Sep 1981 | 6o | 38 | G2 |
| 26 Sep 1981 | 5o | 32 | G1 |
| 27 Sep 1981 | 5- | 21 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| September 1980 | 8.0 | 0 | 0 |
| September 1981 | 12.5 | 4 | 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 12.5 in September 1981, No. 548 of 1138 months since 1932; 4 days reached G1 or higher.