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Geomagnetic activity in September 2011
Mean Ap12.3No. 564 of 1138
G1+ days9
G3+ days0
Max Ap4010 Sep 2011
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 9 Sep 2011 | 6- | 30 | G2 |
| 10 Sep 2011 | 6- | 40 | G2 |
| 12 Sep 2011 | 5- | 27 | G1 |
| 13 Sep 2011 | 5- | 18 | G1 |
| 17 Sep 2011 | 5+ | 32 | G1 |
| 26 Sep 2011 | 6+ | 38 | G2 |
| 27 Sep 2011 | 6- | 30 | G2 |
| 28 Sep 2011 | 5- | 20 | G1 |
| 29 Sep 2011 | 6- | 24 | G2 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| September 2010 | 5.4 | 0 | 0 |
| September 2011 | 12.3 | 9 | 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 12.3 in September 2011, No. 564 of 1138 months since 1932; 9 days reached G1 or higher.