Kp index — 1999
The Kp archive
GFZ definitive record · 3-hour UTC intervals · 1932 → 2026-07-31
Max Kp
8.0
22 Sep · G4
Storm nights
12
G1×5G2×6G4×1
Time at storm level
12.9%
intervals at Kp ≥ 5−
Avg Kp
2.8
all intervals
Tap a day — its eight intervals open here.
Highlights
- G4 storm · Sep 22–23 · peak Kp 8.0
1999 · the year at a glance — storm nights by month · year peak Kp 8.0
All-time record: Kp 9.0 — reached on 27 days, most recently 2024-05-11.