Aurora & Space WeatherHome › Geomagnetic history › 1991
Geomagnetic activity in August 1991
Mean Ap30.5No. 24 of 1138
G1+ days19
G3+ days5
Max Ap7419 Aug 1991
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 1 Aug 1991 | 6o | 36 | G2 |
| 2 Aug 1991 | 6+ | 52 | G2 |
| 3 Aug 1991 | 6+ | 42 | G2 |
| 4 Aug 1991 | 6o | 44 | G2 |
| 5 Aug 1991 | 5+ | 32 | G1 |
| 6 Aug 1991 | 6o | 32 | G2 |
| 7 Aug 1991 | 5+ | 16 | G1 |
| 11 Aug 1991 | 5- | 24 | G1 |
| 12 Aug 1991 | 7+ | 64 | G3 |
| 14 Aug 1991 | 5+ | 19 | G1 |
| 15 Aug 1991 | 5o | 36 | G1 |
| 18 Aug 1991 | 6o | 26 | G2 |
| 19 Aug 1991 | 8- | 74 | G4 |
| 20 Aug 1991 | 8- | 67 | G4 |
| 21 Aug 1991 | 6o | 41 | G2 |
| 22 Aug 1991 | 7o | 48 | G3 |
| 27 Aug 1991 | 7- | 37 | G3 |
| 30 Aug 1991 | 6+ | 49 | G2 |
| 31 Aug 1991 | 6o | 52 | G2 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| August 1990 | 18.7 | 12 | 2 |
| August 1991 | 30.5 | 19 | 5 |
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 30.5 in August 1991, No. 24 of 1138 months since 1932; 19 days reached G1 or higher.