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HF Propagation and Solar-Terrestrial Data

Free, live solar and geomagnetic data with HF band conditions, a gray line map, space weather forecasts, converters and embeddable widgets, built for radio amateurs.

Conditions right now

Current conditions: solar flux index 115, sunspot number 66, A-index 20, Kp 2.3 (quiet geomagnetic field), X-ray flux B6.3, solar wind 450 km/s.

Solar flux (SFI)

115

Good

Sunspots

A-index (24 h)

Active

Kp index

2.3

Quiet

Aurora limit: 63°

X-ray

B6.3

Solar wind

450 km/s

4.1 p/cm³

Bz (IMF)

1.1 nT

North (favourable)

80–40 m Fair day Good night

30–20 m Good day Fair night

17–15 m Fair day Fair night

12–10 m Fair day Poor night

Open the live dashboard HF band conditions

Live data and conditions

Live DataSolar flux, sunspots, A/K index, X-ray, solar wind and Bz in real time.HF BandsDay and night conditions for every HF band, plus VHF aurora and E-skip outlook.Gray LineLive day/night terminator and subsolar point for low-band DX.ForecastNOAA 3-day outlook, predicted Kp and the latest space weather alerts.Solar ImagesThe Sun in many wavelengths, the corona and the aurora ovals.

Propagation tools

Sunrise, Sunset and Gray Line by Grid LocatorSunrise, sunset and gray line windows for any Maidenhead locator.HF Propagation What-If SimulatorMove the sliders and watch HF band conditions change.SFI to Sunspot Number ConverterConvert solar flux (F10.7) to sunspot number and back.Kp to A-Index ConverterKp, ap and A-index conversion with the full table and G-scale.Solar Flare X-Ray Class ConverterFlare class to W/m² and the NOAA radio blackout scale.

WidgetsLive banners for your website, club page or forum signature.Data FeedsJSON, XML and RSS feeds with a documented format.

Learn how propagation works

What Is HF Propagation?HF propagation explained for radio amateurs: how the ionosphere bends 3-30 MHz signals, why bands open and close, and what MUF and skip distance mean.Solar Flux Index (SFI) ExplainedWhat the 10.7 cm solar flux index (SFI, F10.7) is, how it is measured, and which SFI values open 20, 15, 12 and 10 metres for radio amateurs.K-Index and A-Index ExplainedWhat the geomagnetic K-index, Kp and A-index mean for HF propagation, how Kp converts to ap, and when polar paths and low bands start to suffer.Gray Line Propagation for DXWhat the gray line (day/night terminator) is, why signals travel unusually well along it at dawn and dusk, and how to time DX contacts on the low bands.HF Bands by Day and NightWhich HF bands work during the day and which at night, from 160 m to 10 m: typical behaviour, best times and what changes with the solar cycle.FAQAnswers to the most common propagation questions.

Solar-terrestrial data for HF operators

Whether you chase DX on 20 metres, work the low bands at night or wait for a 6 metre opening, the same few numbers decide what is possible. The solar flux index tells you how high in frequency the ionosphere can reflect, the K-index and A-index tell you how disturbed the geomagnetic field is, and the X-ray flux warns you about flare-driven radio blackouts.

This section collects those indicators from NOAA’s Space Weather Prediction Center, refreshes them every few minutes and turns them into an easy estimate of band conditions from 160 m to 6 m, for day and night. You can follow the day/night terminator on the gray line map, check the 3-day forecast and alerts, and look at the Sun itself in the solar image gallery.

Everything is free. Add a live banner to your club website with the widgets, or build your own app on the JSON, XML and RSS feeds. To understand how the estimates are produced and where they fall short, read the methodology.

Data: NOAA Space Weather Prediction Center, NASA SDO. Band conditions are estimates computed by Map For HAM and are indicative only. Methodology and credits · Data feeds · Widgets