Kp index — September 1957
The Kp archive
GFZ definitive record · 3-hour UTC intervals · 1932 → 2026-07-31
Max Kp
9.0
4 Sep · G5
Storm nights
16
G1×3G2×4G3×1G4×7G5×1
Time at storm level
34.6%
intervals at Kp ≥ 5−
Avg Kp
3.7
all intervals
Tap a day — its eight intervals open here.
Highlights
- G5 storm · Sep 1–6 · peak Kp 9.0
- Strongest activity since September 1946
1957 · the year at a glance — storm nights by month · year peak Kp 9.0
All-time record: Kp 9.0 — reached on 27 days, most recently 2024-05-11.