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Geomagnetic activity in August 1999
Mean Ap14.8No. 372 of 1138
G1+ days9
G3+ days0
Max Ap3620 Aug 1999
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 15 Aug 1999 | 5- | 19 | G1 |
| 16 Aug 1999 | 5+ | 29 | G1 |
| 17 Aug 1999 | 5+ | 29 | G1 |
| 18 Aug 1999 | 5o | 28 | G1 |
| 20 Aug 1999 | 6- | 36 | G2 |
| 23 Aug 1999 | 6- | 31 | G2 |
| 24 Aug 1999 | 6- | 29 | G2 |
| 30 Aug 1999 | 5o | 23 | G1 |
| 31 Aug 1999 | 5o | 22 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| August 1998 | 17.8 | 7 | 2 |
| August 1999 | 14.8 | 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 14.8 in August 1999, No. 372 of 1138 months since 1932; 9 days reached G1 or higher.