Space weather right now
The state of the near-Earth space environment, from NOAA's Space Weather Prediction Center. Everything here is UTC, which is how space weather is quoted everywhere — no local-time conversion to get wrong.
Geomagnetic activity
Kp is the planetary index of geomagnetic disturbance, derived from magnetometers around the world and reported every three hours. It is quasi-logarithmic, so the distance from 4 to 5 is not the distance from 8 to 9 — a G1 storm at Kp 5 is an ordinary event, and Kp 8 is a decade-scale one. For HF operators the practical reading is simple: as Kp climbs, the high bands degrade first and paths crossing the auroral zone go first of all.
Flares
Solar flares announce themselves on the X-ray channel before anything else arrives. The effect on radio is immediate and one-sided: X-rays reach Earth at the speed of light and ionise the D layer on the sunlit hemisphere, which absorbs HF rather than refracting it. An M-class flare takes the low bands out for minutes; an X-class flare can take the whole sunlit side out for an hour. The night side notices nothing.
Solar wind
Speed, density and field come from NOAA's Real Time Solar Wind stream, fed by whichever spacecraft is on station at the L1 point about a million miles upstream — currently IMAP and ACE, previously DSCOVR. That upstream position buys roughly 15 to 60 minutes of warning, depending on how fast the wind is moving. Bz is the one to watch. When the interplanetary magnetic field tilts southward it opposes Earth's field and the two reconnect, letting energy in; sustained negative Bz with elevated speed is the signature that precedes most storms. The chart names the spacecraft it is actually drawing.
Solar activity
F10.7 is the 10.7 cm solar radio flux, measured daily at Penticton, and it tracks solar EUV output closely enough to stand in for it. It sets the ceiling on HF: the higher it runs, the higher the maximum usable frequency, and the more the upper bands come alive.
Notes on the data
Sources, refresh behaviour, and the caveats worth knowing
Seven unauthenticated JSON feeds from
services.swpc.noaa.gov:
noaa-scales, noaa-planetary-k-index-forecast,
goes/primary/xrays-1-day,
goes/primary/xray-flares-7-day, 10cm-flux-30-day,
and Real Time Solar Wind rtsw/rtsw_wind_1m +
rtsw/rtsw_mag_1m. No API key.
The page prefers live data. On load it renders a snapshot baked in at build time, then tries to fetch the feeds directly from your browser; if that works the badge turns green and the board refreshes every five minutes. If your browser can't reach NOAA the snapshot stays up and the badge says so.
The Kp series carries observed, estimated and predicted values in one feed; predicted bars are drawn faded and the dashed rule marks where the record stops. NOAA's forecast is issued three times daily, so the forecast tail can be several hours old even when the observed values are current.
Solar wind is measured at L1, not at Earth — the lead time is the travel time from there, which varies with speed. RTSW interleaves several spacecraft in one array, and they disagree: two instruments reporting the same minute can differ by ten km/s or more. This page picks a single stream rather than averaging them, so the trace is one instrument's view rather than an artefact of the merge.
Flare classes are derived from the 0.1–0.8 nm long channel, where each letter is one decade of flux. GOES also reports a short channel; it is not plotted here.
Source: NOAA Space Weather Prediction Center (products), GOES and DSCOVR. Public domain. Not affiliated with NOAA. Snapshot baked August 24, 2026 at 2:12 PM CDT.