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Geomagnetic activity in July 1939
Mean Ap19.0No. 179 of 1138
G1+ days14
G3+ days4
Max Ap945 Jul 1939
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 3 Jul 1939 | 7- | 45 | G3 |
| 4 Jul 1939 | 7- | 43 | G3 |
| 5 Jul 1939 | 7+ | 94 | G3 |
| 6 Jul 1939 | 5- | 17 | G1 |
| 11 Jul 1939 | 5- | 12 | G1 |
| 12 Jul 1939 | 5- | 15 | G1 |
| 14 Jul 1939 | 5+ | 31 | G1 |
| 16 Jul 1939 | 5+ | 26 | G1 |
| 19 Jul 1939 | 5o | 12 | G1 |
| 20 Jul 1939 | 6o | 47 | G2 |
| 21 Jul 1939 | 7+ | 36 | G3 |
| 22 Jul 1939 | 5- | 21 | G1 |
| 25 Jul 1939 | 5- | 14 | G1 |
| 26 Jul 1939 | 6- | 35 | G2 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| July 1938 | 13.2 | 9 | 1 |
| July 1939 | 19.0 | 14 | 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 19.0 in July 1939, No. 179 of 1138 months since 1932; 14 days reached G1 or higher.