Solar Conditions & HF Propagation

Overall solar activity at 10.7cm. From 62.5 to 300 — higher is better.

Derived from number of sunspots + groups. 0 to 250 — higher is better.

Overall activity of Earth's magnetic field, based on the K-index.

Speed in km/s. Typically 0–1000 — lower is better; contributes noise.

Background noise contributed by solar activity.

Average geomagnetic activity. Lower is better.

Geomagnetic field disturbance, 0 to 9. Lower is better.

X-ray intensity in the ionosphere. A, B, C, M, X indicates magnitude.

Total solar radiation at 30.4nm, emitted by ionized helium.

Density of charged protons in the solar wind. Impacts the E-layer.

Density of charged electrons in the solar wind. Impacts the E-layer.

Highest frequency that reflects back from the F2 layer (MHz).

Maximum usable frequency for sky-wave propagation (MHz).

Aurora activity level (0–100). Higher = more active aurora.

Southernmost latitude where aurora may be visible.

Interplanetary magnetic field. Negative Bz drives geomagnetic storms.

Geomagnetic field disturbance overnight. Lower is better.

Northern hemisphere

North America

Europe

Europe

Europe