Kp index — April 1940
The Kp archive
GFZ definitive record · 3-hour UTC intervals · 1932 → 2026-07-31
Max Kp
8.0
3 Apr · G4
Storm nights
6
G1×1G3×3G4×2
Time at storm level
10.4%
intervals at Kp ≥ 5−
Avg Kp
2.3
all intervals
Tap a day — its eight intervals open here.
Highlights
- G4 storm · Apr 1–3 · peak Kp 8.0
1940 · 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.