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Geomagnetic activity in January 1999
Mean Ap10.3No. 726 of 1138
G1+ days4
G3+ days1
Max Ap4013 Jan 1999
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 13 Jan 1999 | 7o | 40 | G3 |
| 14 Jan 1999 | 5+ | 29 | G1 |
| 15 Jan 1999 | 5- | 20 | G1 |
| 23 Jan 1999 | 5o | 21 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| January 1998 | 7.5 | 1 | 0 |
| January 1999 | 10.3 | 4 | 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.
← December 1998February 1999 →
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Mean Ap 10.3 in January 1999, No. 726 of 1138 months since 1932; 4 days reached G1 or higher.