Live · NOAA forecast for the next 30 to 90 minutes, updated every 10 minutes
Aurora
The glowing ring is NOAA's forecast of where aurora may be visible soon. Aurorae light up in rings around the magnetic poles when charged particles from the Sun crash into the upper atmosphere.
Particles from the Sun
The Sun constantly blows out a thin stream of charged particles, the solar wind, and sometimes hurls huge clouds of them in eruptions called coronal mass ejections. The Earth's magnetic field turns most of them aside but steers some down towards the regions around the magnetic poles.
Why it glows
The particles hit oxygen and nitrogen 100 to 300 km up, far above the clouds, and make them give off light. Oxygen glows green, and red at the greatest heights; nitrogen adds blue and purple at the lower edge.
The auroral oval
Aurorae appear in a ring around each magnetic pole, usually roughly 1,500 to 3,000 km from it: over Alaska, northern Canada, Iceland, northern Scandinavia and Siberia in the north, and over Antarctica in the south, where they are called the aurora australis, the southern lights.
Storms and the Kp index
The Kp index, from 0 to 9, measures how strongly the magnetic field is being shaken. NOAA calls Kp 5 a minor geomagnetic storm (G1) and Kp 9 an extreme one (G5). The stronger the storm, the further the ring spreads towards the equator. In May 2024, during the first G5 storm since 2003, aurorae were seen in Mexico and recorded by cameras in Ladakh in northern India.
Reading the forecast
The colours show the chance of aurora being seen overhead, from NOAA's OVATION model, which turns measurements of the solar wind made by spacecraft 1.5 million km towards the Sun into a forecast about an hour ahead. It is only visible at night, with a dark, clear sky.
Did you know?
The same storms that light up the sky can disturb satellites, GPS and radio, and in 1989 a geomagnetic storm caused a nine-hour blackout across Quebec in Canada.