Space Weather

Solar radio flux at 10.7 cm — a proxy for solar activity. The higher it is, the more ionised the F layer, and the better the HF / 11 m propagation. Typical range: 65 (solar minimum, bands dead above 14 MHz) up to 300+ at solar peak. Above 100, daily 10/11 m openings become common; above 150, strong DX is the rule.

10.7 cm radio flux (SFU, daily)

Planetary K index — geomagnetic disturbance on a logarithmic 0–9 scale, sampled every 3 hours. Low values mean a quiet magnetosphere and clean HF; from 5 onward NOAA calls it a G1+ storm, with polar paths absorbed and auroras lighting up. Quiet (< 3) is what you want for serious DX.

Planetary K (0–9, every 3 h)

Running daily A index — derived from the eight 3-hour K samples but on a linear scale, so it captures the magnitude of geomagnetic activity rather than its severity step. 0–7 is calm, 30+ is a storm. Useful to see if the past day was rough even when the instantaneous Kp is now quiet.

Running daily A index (linear)