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Current planetary Kp
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What is the Kp index?
The planetary K-index (Kp) is a global measurement of geomagnetic activity on a 0–9 scale. It is calculated every three hours from magnetometer data at 13 observatories around the world, and published by the GFZ Potsdam research centre. NOAA's Space Weather Prediction Center issues a 3-day Kp forecast that drives every aurora prediction site in the world — including this one.
Higher Kp pushes the aurora oval further from the magnetic pole. In Australia, that means a higher Kp brings the Aurora Australis further north — from Tasmania (Kp 5+), to Victoria and South Australia (Kp 6+), then to NSW and southern WA (Kp 7+), and during severe storms all the way to Brisbane (Kp 8+).
Kp index vs the BOM K-index
Australia's Bureau of Meteorology Space Weather Services publishes its own K-index using local magnetometers (Learmonth, Canberra, Hobart, Macquarie Island). It uses the same 0–9 scale but can run slightly different from the planetary Kp during regional disturbances. For aurora forecasting in Australia, the planetary Kp above gives the best lead time and matches NOAA's G-storm scale (G1=Kp5, G2=Kp6, G3=Kp7, G4=Kp8, G5=Kp9).
Kp index — what it means in Australia
The planetary Kp index runs 0–9. Higher Kp pushes the aurora further from the magnetic pole, making it visible from lower latitudes.
Kp 0–3 — Quiet
No aurora visible from mainland Australia. Possible faint glow at extreme southern Tasmania.
Kp 4 — Unsettled
Camera-only horizon glow possible from southern Tasmania.
Kp 5 (G1) — Minor storm
Visible aurora across Tasmania. Faint glow on horizon from Victoria, South Australia and far-south WA.
Kp 6 (G2) — Moderate storm
Bright aurora overhead in Tasmania. Clearly visible from VIC, SA and southern WA coasts.
Kp 7 (G3) — Strong storm
Vivid colour visible from VIC/SA/WA. Reaches as far north as Sydney and Perth.
Kp 8 (G4) — Severe storm
Aurora visible from NSW, WA and southern QLD. Once-a-year event.
Kp 9 (G5) — Extreme storm
Aurora visible from the entire continent including Brisbane and Darwin. Once-a-decade event.
Where next
Kp Index FAQs
Kp data: NOAA Space Weather Prediction Center · GFZ Potsdam. Australian context: BOM Space Weather Services.