HF Propagation Prediction & Live Solar Conditions
9M2PJU HF Propagation Prediction is a free online tool for amateur radio (ham radio)
operators to monitor live HF band conditions and predict signal propagation reliability.
It pulls real-time space weather data from NOAA SWPC, including the solar flux index (SFI),
sunspot number (SSN), K-index, A-index, solar wind speed, magnetic field (Bz) and X-ray
solar flare class, then combines it with a VOACAP-style physics engine to estimate the
maximum usable frequency (MUF) and lowest usable frequency (LUF) for any DX path.
Features
- Live NOAA solar indices: SFI, SSN, K-index, A-index
- HF band conditions for 80m, 40m, 30m, 20m, 17m, 15m, 12m, 10m and 6m
- MUF and LUF 24-hour forecast chart
- Best HF band calculator for any transmitter – receiver path
- Great-circle DX distance, short path and long path beam heading
- Greyline propagation window alerts at sunrise and sunset
- Solar wind speed, Bz magnetic field and X-ray flare monitoring
- DX presets for common target regions (Japan, USA, Europe, Oceania and more)
How the propagation engine works
The prediction engine models HF ionospheric propagation using solar cycle phase, diurnal
(day/night) MUF variations and path geometry (number of hops). It samples reliability
across nine HF bands from 3.5 MHz to 50 MHz and returns the single best
frequency for the selected path, date and UTC time.
This application requires JavaScript to run. Please enable JavaScript in your browser to
use the interactive propagation map and live solar dashboard.