In 2003 the planetary Kp peaked at 9.0 (G5) on 29 October 2003: 158 storm nights over the year, and 15.5% of its three-hour intervals at storm level.
| Month | Max Kp | Peak day | Storm nights | By class | At storm level | Avg Kp |
|---|---|---|---|---|---|---|
| January | 5.7 | 25 | 9 | G1×8G2×1 | 4.8% | 2.4 |
| February | 5.7 | 2 | 6 | G1×4G2×2 | 7.1% | 2.9 |
| March | 6.3 | 31 | 16 | G1×11G2×5 | 17.3% | 3.2 |
| April | 6.0 | 29 | 13 | G1×11G2×2 | 11.3% | 3.2 |
| May | 8.3 | 29 | 17 | G1×7G2×6G3×3G4×1 | 19.4% | 3.4 |
| June | 6.7 | 18 | 16 | G1×9G2×6G3×1 | 17.9% | 3.5 |
| July | 6.7 | 12 | 13 | G1×7G2×5G3×1 | 14.1% | 2.9 |
| August | 7.3 | 18 | 15 | G1×8G2×5G3×2 | 18.5% | 3.2 |
| September | 7.0 | 17 | 8 | G1×4G2×3G3×1 | 13.8% | 2.8 |
| October | 9.0 | 29 | 16 | G1×7G2×4G3×2G4×1G5×2 | 25.0% | 3.2 |
| November | 8.7 | 20 | 17 | G1×8G2×6G3×2G4×1 | 24.6% | 3.4 |
| December | 5.7 | 5 | 12 | G1×10G2×2 | 11.3% | 2.7 |
In the hall of storms: The Halloween storms, 29 October 2003 · Kp 9.0 →
All-time record: Kp 9.0 — reached on 27 days, most recently 2024-05-11.
Ranked from the data: peak Kp, then intervals spent at 9.0. Nicknames and reach notes only where documented.
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