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Geomagnetic activity in July 1999
Mean Ap9.6No. 791 of 1138
G1+ days5
G3+ days1
Max Ap5330 Jul 1999
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 2 Jul 1999 | 5o | 26 | G1 |
| 21 Jul 1999 | 5- | 14 | G1 |
| 22 Jul 1999 | 5- | 25 | G1 |
| 30 Jul 1999 | 8- | 53 | G4 |
| 31 Jul 1999 | 5+ | 28 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| July 1998 | 10.8 | 6 | 0 |
| July 1999 | 9.6 | 5 | 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 9.6 in July 1999, No. 791 of 1138 months since 1932; 5 days reached G1 or higher.