Everything I like to check before switching the radio on: the state of the Sun, the ionosphere and the magnetic field, updated live.

Now

Kp–
SFI–
X-ray–

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Kp index, last 72 h (red bars = geomagnetic storm)
Solar X-rays, last 6 h (log scale, classes A–X)

Data source: NOAA SWPC

Band conditions

Estimate per band, day and night, for Europe (N0NBH / hamqsl.com):

Solar and HF propagation conditions
Solar data and propagation forecast: N0NBH / hamqsl.com

Maps and graphs

World MUF
World MUF — maximum usable frequency, measured by ionosondes. (prop.kc2g.com)
Day and night
Day and night — solar map with the terminator line and MUFs. (hamqsl.com)
D-RAP absorption
D-RAP absorption — areas where the D layer is absorbing HF right now. (NOAA SWPC)
Aurora (northern hemisphere)
Aurora (northern hemisphere) — 30-minute forecast; useful for VHF aurora scatter. (NOAA SWPC)
Solar flux and sunspots, 30 days
Solar flux and sunspots, 30 days — recent evolution of SFI and sunspot number. (hamqsl.com)

How to read these values

  • SFI (10.7 cm solar flux): the higher it is, the more ionised the ionosphere gets by day. Below ~80 only the low bands work well; above ~120 15 m and 20 m open nicely; above ~150 10 m does too.
  • Kp (0–9): measures how disturbed the Earth’s magnetic field is. Up to 2 is quiet; from 5 (G1) there is a geomagnetic storm, with noise and fading at high latitudes and a lower MUF.
  • Solar X-rays (classes A, B, C, M, X): an M or X flare ionises the D layer on the sunlit side and absorbs HF, causing a radio blackout that can last minutes to hours, stronger on the low bands.
  • MUF: the highest frequency the ionosphere reflects on a given path. Above it the signal escapes to space; below it, it is reflected. It pays to operate a little below the path’s MUF.
  • D-RAP: where and how much the D layer is absorbing HF, by frequency. Handy to understand why a band “dies” during the day.

The values in this panel are read in your browser from public services; if one fails, the links below lead to the source.

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