Finland is one of the best places in the world for viewing Northern Lights (aurora borealis). The probability of catching them is highest in Lapland but Oulu is not far behind. According to the Finnish Meteorological Institute, we can see Northern Lights about 25% of the nights here – as long as there’s darkness and there are no clouds in the sky.

In the summer the sky doesn’t get dark enough in Finland to see auroras. At midsummer the Sun barely touches the horizon in Oulu. But in September darkness begins to overpower light, opening a window of opportunity to watch Northern Lights in Oulu all the way to April.

And what a spectacle we can enjoy here when the lights arrive, swirling and dancing. Sometimes they look like curtains, other times they’re like long trails in the sky. Most of the time they’re green, but sometimes they’re red or purple.

What causes this beautiful natural phenomenon? Here’s an explanation by Thomas Kast, a professional photographer and tour guide based in Oulu who specialises in taking photos of the Northern Lights.

“Northern Lights occur when eruptions on the Sun release charged particles into space that interact with the Earth’s atmosphere. The results of these collisions are glowing emissions that are visible on clear nights around the Arctic Circle.”

Oulu is located about 200 km south of the Arctic Circle. To residents’ and visitors’ delight, auroras have been occurring at an increasing frequency recently. What’s the reason for that?

“It’s got to do with the solar cycle,” says Thomas Kast. “The Sun has an 11-year cycle that includes passing through a Solar Maximum and a Solar Minimum. There are more Northern Lights during Solar Maximum, the next of which is in 2026. It’s a lucky coincidence that it’s the same year when Oulu is Europe’s Culture Capital. We can expect to see a lot of Northern Lights that  year.

“It’s only 2023 but we have already started seeing more Northern Lights in Oulu as they tend to occur increasingly frequently at either side of the Solar Maximum.”

Thomas Kast has joined forces with Tietomaa, Oulu’s Science Centre, to create a Northern Lights project that’s part of Oulu2026’s cultural programme.

“The title of the project is Aurora Revelare and it consists of two parts: one is an interactive exhibition in Tietomaa that will cover the scientific and cultural aspects of Northern Lights. For instance, we’ll explore what Northern Lights mean in different Sami cultures, what myths and traditions are related to them. We’ll also give tips to people on how to find Northern Lights and how to interpret space weather forecasts.

“The second part of the project is to take people out to nature to hunt the lights. There will be evening tours in the Oulu area and also longer ones taking two to three days when we travel north and east of Oulu, but still stay in the Oulu2026 area.”

And what’s Thomas’ best tip for people who can’t wait for the tours in 2026 and want to see Northern Lights in Oulu now?

“Get out of the city centre. Find a place away from street lights, ideally a field or a meadow or a river, facing north. My favourite spots are places along the river where the water doesn’t freeze. I love reflections of the Northern Lights on water. They’re so beautiful.”

ISES RWC Finland provides real-time information on Northern Lights in Finland.

Text and video by Erika Benke