Kp index — September 1947
The Kp archive
GFZ definitive record · 3-hour UTC intervals · 1932 → 2026-07-31
Max Kp
7.7
25 Sep · G4
Storm nights
16
G1×7G2×5G3×3G4×1
Time at storm level
32.1%
intervals at Kp ≥ 5−
Avg Kp
3.6
all intervals
Tap a day — its eight intervals open here.
Highlights
- G4 storm · Sep 22–25 · peak Kp 7.7
1947 · the year at a glance — storm nights by month · year peak Kp 8.7
All-time record: Kp 9.0 — reached on 27 days, most recently 2024-05-11.