Operating now? Identify at least every 10 minutes and at the end of each contact (47 CFR 97.119). Free station ID timer for any radio · On an IC-7760? Learn more about CallMinder.
How to use this page
- Check the update time below — values refresh at most once per hour.
- Read NOAA space weather cards for flux, Kp, and storm scales.
- Compare day vs night HF band ratings before you pick a band to call CQ.
- Treat ratings as a guide only; listen on the band and use your own judgment.
Loading latest snapshot…
NOAA space weather
Public data from the Space Weather Prediction Center. Observation times appear on each card when the feed includes them.
HF band ratings (N0NBH / HAMQSL.com)
What these numbers mean
- Solar flux (F10.7) — higher usually means better daytime HF, especially higher bands.
- Kp / A index — geomagnetic activity. Higher Kp often means poorer paths, more absorption, and aurora-related noise.
- X-ray class — flare activity. Strong flares can cause shortwave fadeouts on the sunlit side of Earth.
- Solar wind / Bt / Bz — wind speed and magnetic field; southward Bz often couples more energy into the magnetosphere.
- R / S / G scales — NOAA radio blackout, solar radiation, and geomagnetic storm scales.
Band ratings are a volunteer summary, not a guarantee of any path. Always listen and use your own judgment. MUF/foF2 maps are not shown here (license limits on that data).
When you’re on the air with an IC-7760, CallMinder can help with ID timing — you remain responsible for FCC station identification.
About CallMinderSources and credits
Data: NOAA Space Weather Prediction Center — swpc.noaa.gov. Free public data; not an endorsement by NOAA.
N0NBH / HAMQSL.com — hamqsl.com/solar.html. We keep people-credits from the feed. Refresh at most hourly. That feed may change or end. We do not use GIRO MUF/foF2 fields from it.
Privacy: this page does not use accounts, email capture, or analytics cookies. Exam practice progress is saved only in your browser. See our Privacy Policy.