How to see the northern lights this winter

The northern lights, or aurora borealis, are expected to be stronger than they have been for at least a decade over the next few months. Here is how to spot them

By Abigail Beall

26 September 2023

The northern lights over Culloden in Scotland

Michael Carver/Getty Images

Earlier this week in the northern hemisphere, the northern lights, or aurora borealis, were seen creating bright displays further south than usual. These expanses of green, purple and red flickering glows in the night sky, created by particles from the sun, are a wonder to behold. But if you missed them, don’t worry, there is still a chance to see them.

The northern lights tend to be brighter when the sun has been more active. Recent observations of sunspots, a measure of how active the sun is, show a dramatic increase from this time last year, and we are approaching the expected peak of the 11-year solar cycle in 2024 or 2025. This means that over the next few months in the northern hemisphere, the northern lights will probably be stronger than they have been for at least a decade.

What are the northern lights?

The northern lights are generated by the solar wind – a stream of charged particles travelling from the outer layer of the sun, or corona. Bursts of solar wind, called solar flares, slam into Earth’s magnetic field, which acts like a shield around the planet that deflects most of the particles. But at its weakest points around the poles, some particles penetrate into the upper atmosphere, where they collide with and excite, or energise, gas molecules. As these molecules lose energy again, they release photons of light that make the auroras.

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The type of excited molecule, along with the altitude of the collisions, determines the colour of each aurora. The most common are pale yellow and green from oxygen molecules around 120 to 180 kilometres up. Less frequent are red auroras, generated from oxygen around 200 km above the ground, while red-purple auroras come from nitrogen below 100 km.

Where will the northern lights be visible?

The stronger the solar flare, the further south the northern lights will be visible. The particles take around a day to travel to Earth, so we can predict up to a day in advance how strong the aurora is likely to be. Keep an eye on forecasts and aurora prediction apps.

When is the best time to see the northern lights?

If the solar wind is active, an aurora can be seen as soon as it is dark. But the level of activity can change quickly, so your best bet is to keep an eye on live reports of solar activity.