Aurora & Space WeatherHome › Geomagnetic history › 1973
Geomagnetic activity in April 1973
Mean Ap29.8No. 26 of 1138
G1+ days18
G3+ days4
Max Ap911 Apr 1973
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 1 Apr 1973 | 8+ | 91 | G4 |
| 2 Apr 1973 | 7o | 54 | G3 |
| 3 Apr 1973 | 5+ | 26 | G1 |
| 11 Apr 1973 | 5- | 24 | G1 |
| 13 Apr 1973 | 7+ | 46 | G3 |
| 14 Apr 1973 | 8- | 57 | G4 |
| 16 Apr 1973 | 6+ | 60 | G2 |
| 17 Apr 1973 | 6o | 51 | G2 |
| 18 Apr 1973 | 5+ | 46 | G1 |
| 19 Apr 1973 | 6o | 42 | G2 |
| 20 Apr 1973 | 6- | 46 | G2 |
| 21 Apr 1973 | 5+ | 42 | G1 |
| 22 Apr 1973 | 6o | 44 | G2 |
| 23 Apr 1973 | 5- | 25 | G1 |
| 26 Apr 1973 | 6- | 28 | G2 |
| 27 Apr 1973 | 5- | 26 | G1 |
| 28 Apr 1973 | 5+ | 26 | G1 |
| 29 Apr 1973 | 6o | 59 | G2 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| April 1972 | 10.9 | 7 | 0 |
| April 1973 | 29.8 | 18 | 4 |
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 29.8 in April 1973, No. 26 of 1138 months since 1932; 18 days reached G1 or higher.