When can I see the Northern Lights? Aurora Borealis UK forecast explained

The Northern Lights were seen across the UK this month amid a 'once in a generation' geomagnetic storm
The Northern Lights were seen across the UK this month amid a 'once in a generation' geomagnetic storm -Credit:Getty Images/iStockphoto

The Northern Lights took the UK's breath away earlier this month as their spectacular colours lit up the skies across the North East and beyond, thanks to the most powerful solar storm in decades.

Otherwise known as the aurora borealis, these captivating lights are caused by activity on the surface of the sun, when solar storms on the star's surface give out huge clouds of electrically charged particles which eventually collide with the earth. The dancing colours we see in the night sky are the result of these particles becoming captured in the Earth's magnetic field and slamming into atoms and molecules in our atmosphere, up to thousands of miles above the surface of our planet.

The Northern Lights can give off different colours depending on the altitude at which the solar particles collide with our atmosphere, from green, blue or purple to pink, yellow or red - many of which were seen on the night of May 10. Whether you missed last week's celestial show or are hoping to get a glimpse of them again, here's everything you need to know about seeing the Northern Lights.

How can I check if the Northern Lights are due to appear?

The best way to check up on the Northern Lights on an hour-by-hour basis is via the Aurora Watch UK website, which is a free service offering alerts of when the phenomenon may be visible from the UK. The website is run by scientists in the Space and Planetary Physics group at Lancaster University's Department of Physics, and uses a four-tier alert system.

This alert system is colour-coded, making it quick and easy to read if, like many, you're not familiar with what the ins and outs of the solar wind forecasts and Kp Index mean. On Aurora Watch, the colours are as follows:

  • Green - No significant activity: Aurora is unlikely to be visible by eye or camera from anywhere in the UK.

  • Yellow - Minor geomagnetic activity: Aurora may be visible by eye from Scotland and may be visible by camera from Scotland, northern England and Northern Ireland.

  • Amber - Possible aurora: Aurora is likely to be visible by eye from Scotland, northern England and Northern Ireland; possibly visible from elsewhere in the UK. Photographs of aurora are likely from anywhere in the UK.

  • Red: Aurora likely: It is likely that aurora will be visible by eye and camera from anywhere in the UK.

The Met Office also offers a daily Space Weather forecast, which analyses geomagnetic activity every 24 hours to make aurora predictions. Additionally, there are various other websites, apps and social media groups out there dedicated to Northern Lights hunters, which provide daily updates and advice.

When and where is my best chance of seeing the Northern Lights?

The Northern Lights are most active during the Equinox and Solstice in March/April and September/October. They are best witnessed in Scotland, North England, North Wales and Northern Ireland - but under severe space weather conditions, the lights can be seen throughout the UK.

The best conditions to view the lights are when the sky is dark and clear of any clouds, as cloud cover ultimately blocks the view of the light. Ideally, you will want to find yourself a viewing spot in a remote area, away from any light pollution, facing the northern horizon - north facing coasts produce some of the best viewing locations, according to the Met Office.

It must be dark in order to see the Northern Lights - they can and often do appear during daylight hours, but are not visible to us. After sunset and before sunrise is when you should be heading out - right now, this is from approximately 9pm until 5am in the UK, with the darkest and most favourable conditions being from around 10.30pm into the early hours.

One simple check recommended by Aurora Watch is: Can you see the stars? If so this means you're seeing the night sky and clouds or light pollution are not obstructing your view, and you will therefore be able to see the Northern Lights if and when they appear.

How to understand a Northern Lights forecast

Reading a Northern Lights forecast can be tricky - and it's not always accurate, as the phenomenon is notoriously difficult to predict any further in advance than around two hours before it happens, according to Aurora Zone. However, forecasts can offer a decent guide as to whether you could be in with a chance of seeing the Northern Lights on any one night.

The speed and direction of the solar wind play a crucial role in aurora activity. Solar wind data, such as the speed in kilometres per second (km/s) and the direction (measured in degrees), can help predict the likelihood of geomagnetic storms and Northern Lights visibility, as explained by Iceland's Perlan Museum.

Another indicator is the Kp Index, which is a common way to measure the strength of geomagnetic activity. This index ranges from 0 to 9, with higher values indicating more significant geomagnetic disturbances. A Kp index of 5 or higher is often associated with good Northern Lights viewing opportunities - you can see the latest Kp Index and solar wind predictions on the Space Weather Prediction Center website.