Aurora & Space WeatherGeomagnetic activity in 1991
Mean Ap23.4
G1+141days
G3+38days
G55days
G1+ days by month
- January 1991
- February 1991
- March 1991
- April 1991
- May 1991
- June 1991
- July 1991
- August 1991
- September 1991
- October 1991
- November 1991
- December 1991
Nearby years (G1+ days)
71
56
59
123
104
141
107
108
125
100
41
Top 10 days by Ap
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 5 Jun 1991 | 9- | 196 | G5 |
| 24 Mar 1991 | 9- | 161 | G5 |
| 13 Jul 1991 | 9- | 134 | G5 |
| 25 Mar 1991 | 9- | 130 | G5 |
| 29 Oct 1991 | 8+ | 128 | G4 |
| 13 Jun 1991 | 8- | 120 | G4 |
| 10 Jun 1991 | 8- | 119 | G4 |
| 9 Nov 1991 | 8+ | 119 | G4 |
| 9 Jul 1991 | 8o | 117 | G4 |
| 26 Mar 1991 | 8o | 114 | G4 |
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
1991 had 141 G1+ storm days (No. 7 of 95 years) and 38 G3+ days.