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Geomagnetic activity in September 1971
Mean Ap12.8No. 520 of 1138
G1+ days7
G3+ days1
Max Ap4718 Sep 1971
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 13 Sep 1971 | 5- | 17 | G1 |
| 17 Sep 1971 | 5o | 13 | G1 |
| 18 Sep 1971 | 7- | 47 | G3 |
| 25 Sep 1971 | 6- | 27 | G2 |
| 26 Sep 1971 | 6+ | 21 | G2 |
| 27 Sep 1971 | 6+ | 38 | G2 |
| 30 Sep 1971 | 5- | 23 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| September 1970 | 10.8 | 5 | 0 |
| September 1971 | 12.8 | 7 | 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 12.8 in September 1971, No. 520 of 1138 months since 1932; 7 days reached G1 or higher.