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Geomagnetic activity in April 1981
Mean Ap27.8No. 35 of 1138
G1+ days14
G3+ days3
Max Ap12113 Apr 1981
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 11 Apr 1981 | 6+ | 39 | G2 |
| 12 Apr 1981 | 7o | 96 | G3 |
| 13 Apr 1981 | 8+ | 121 | G4 |
| 14 Apr 1981 | 5o | 27 | G1 |
| 17 Apr 1981 | 5- | 19 | G1 |
| 19 Apr 1981 | 6o | 45 | G2 |
| 20 Apr 1981 | 6+ | 53 | G2 |
| 21 Apr 1981 | 5+ | 41 | G1 |
| 22 Apr 1981 | 5o | 33 | G1 |
| 23 Apr 1981 | 5- | 31 | G1 |
| 24 Apr 1981 | 5- | 22 | G1 |
| 26 Apr 1981 | 7+ | 62 | G3 |
| 27 Apr 1981 | 6o | 43 | G2 |
| 29 Apr 1981 | 5- | 19 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| April 1980 | 11.5 | 8 | 0 |
| April 1981 | 27.8 | 14 | 3 |
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 27.8 in April 1981, No. 35 of 1138 months since 1932; 14 days reached G1 or higher.