G4NSJ – What’s happened to the HF amateur bands? July 25

What’s happened to the HF amateur and broadcast bands?

For the past few weeks, the HF amateur and broadcast bands have been in a terrible state. Initially, I thought I had problems with my aerials, until other people began talking about the dead bands. We’re at the sunspot maximum but, 10 metres has been dismal. 40 metres has been dead as have other bands. It’s the same with the HF broadcast bands. Apart from China Radio, the bands have been quiet.

Here’s a colour-coded 2025 HF Propagation cheat sheet — green is best, yellow is fair, red is poor. Bear in mind that this is a guide.

Frequent Geomagnetic Disturbances

Geomagnetic storms driven by coronal mass ejections (CMEs) and coronal holes have disrupted propagation:

April 2025: Multiple CMEs, strong solar wind, and a Kp index reaching 7.7 dramatically lowered MUFs — at times enabling only below 18 MHz over 3,000 km paths. rsgb.org

May 2025: High-speed solar wind from a massive coronal hole kept Kp elevated for many periods, dragging the solar flux index down to around 1524 — undercutting F-layer MUFs rsgb.org.

June 2025: A coronal hole caused Kp to climb to further suppressing propagation even as Sporadic-E offered some short-skip openings rsgb.org+1.

These unstable geomagnetic conditions make reliable HF skip propagation much more elusive throughout 2025.

What are your findings? Let me know…
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