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Geomagnetic activity in September 2004
Mean Ap8.6No. 885 of 1138
G1+ days5
G3+ days0
Max Ap3214 Sep 2004
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 14 Sep 2004 | 5+ | 32 | G1 |
| 15 Sep 2004 | 5- | 14 | G1 |
| 17 Sep 2004 | 5- | 21 | G1 |
| 18 Sep 2004 | 5o | 15 | G1 |
| 20 Sep 2004 | 5- | 12 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| September 2003 | 18.3 | 8 | 1 |
| September 2004 | 8.6 | 5 | 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 8.6 in September 2004, No. 885 of 1138 months since 1932; 5 days reached G1 or higher.