Northern Lights

Will you see the aurora tonight?

The Northern Lights reach Britain a few times a year, and more often in the years around a solar maximum. Whether you see them depends on three things: how disturbed the Earth's magnetic field is, measured by the Kp index; how far north you are; and whether the sky is clear and dark. This page reads NOAA's space weather forecasts for one postcode and sets them against what that latitude needs and the cloud forecast for the night.

  • Kp forecast, three days
  • Aurora oval edge right now
  • Cloud through the night
  • Sunset to sunrise

How this works

The US National Oceanic and Atmospheric Administration’s Space Weather Prediction Center publishes the planetary Kp index as it is observed, a three-day forecast in three-hour steps issued each morning, and the OVATION model’s map of where aurora is likely in the next half hour. This page takes the forecast Kp for the dark hours at the postcode, compares it with a rule of thumb for the Kp needed at that latitude (about 3 at Shetland, 5 in central Scotland, 6 in northern England, 7 on the south coast), reads the model’s probability at the spot and how far north its 10% edge lies, and adds Open-Meteo’s hourly cloud cover between sunset and sunrise. The verdict is a guide: a strong storm can arrive unforecast, and a forecast one can miss.

Sources

  • NOAA Space Weather Prediction Center: planetary K-index and forecast, 3-day forecast, OVATION aurora model, hemispheric power. US government work in the public domain.
  • Open-Meteo forecast API (cloud cover, sunrise and sunset), CC BY 4.0.
  • Postcodes: postcodes.io / ONS Postcode Directory (OGL v3).