ARRL International DX Contest — CW¶
CW · ARRL · February 21–21, 2026
Storm Impact: G1 geomagnetic storm during the contest
Kp rose from quiet (1.0) to storm level (5.3) during the contest weekend while SFI remained stable at 110. SSN dropped to zero on Feb 22 — confirmed real by SILSO daily data. Radio flux lags sunspot counts, so propagation was sustained despite SSN=0.
Kp trajectory: 1.0 → 5.3 (Saturday evening)
Contest Overview¶
| Contest Window | 2026-02-21 00:00 — 2026-02-22 23:59 UTC |
| Analysis Window | 2026-02-20 — 2026-02-23 (±24h) |
| Mode | CW |
| SFI | 108–111 |
| Kp Range | 1.0–5.3 |
| SSN Note | SSN dropped to 0 on Feb 22 (confirmed real — SILSO daily) |
| Primary Source | RBN signatures |
| Secondary Source | PSKR signatures |
Key Findings¶
- 20m dominated with consistent activity across both days — the DX workhorse
- 40m showed strong nighttime activity with clear day/night transitions
- 15m opened well during daylight hours with SFI at 110
- SSN genuinely dropped to zero on Feb 22 during a G1 storm — SFI remained stable at 110 (radio flux lags)
- 160m activity concentrated in darkness hours as expected — physics validated
- SFI 110 is notably below the 2023–2025 February average (~179) — Solar Cycle 25 may be past its peak
Resources¶
| Resource | Link |
|---|---|
| Full Analysis Notebook | View on GitHub |
| Contest Dataset | Download SQLite |
| IONIS Jupyter | All Notebooks |
The notebook contains the complete analysis with interactive charts: solar timeline, band activity heatmaps, geographic reach maps, day/night classification, SNR distributions, and historical context. The SQLite dataset contains all RBN and PSKR signatures from the analysis window — download it to run the notebook locally or explore the data yourself.
Analysis powered by IONIS — 14 billion propagation observations, 80 MCP tools, and a neural network that learned HF physics from the data.