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Geomagnetic activity in September 2021
Mean Ap6.6No. 1030 of 1138
G1+ days1
G3+ days0
Max Ap2317 Sep 2021
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 17 Sep 2021 | 5+ | 23 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| September 2020 | 8.6 | 4 | 0 |
| September 2021 | 6.6 | 1 | 0 |
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 6.6 in September 2021, No. 1030 of 1138 months since 1932; 1 days reached G1 or higher.