Northern lights in Norway: frequently asked questions

Here are answers to the questions we hear most often about the northern lights in Norway: what they are, when and where to see them, how to read the forecasts, and what to think about before heading out. The answers are short; the links lead to articles that go into depth. If a term is unfamiliar, the glossary can help.

Aurora basics

What is the aurora?

The aurora is light from gases in the upper atmosphere that are struck by charged particles, mainly electrons. The particles gain their energy from the interaction between the solar wind and Earth's magnetic field, which guides them down towards the polar regions. There they collide with oxygen and nitrogen, which give off light. Read more in what the aurora is.

How high up is the aurora?

The aurora forms between roughly 80 and 500 km above the ground. According to Store norske leksikon (the Norwegian encyclopedia), night-time aurora is brightest at 100–120 km, while rays often reach up to 200–300 km. Clouds, by comparison, are only a few kilometres up.

What colours does the aurora have?

The most common colour is yellow-green from oxygen at 557.7 nanometres. Red from oxygen at 630.0 nanometres sits higher up, and blue and violet tones at the lower edge come from nitrogen.

Is the aurora dangerous?

Not to you standing on the ground watching it. NOAA's geomagnetic storm scale describes effects on power grids, satellites, radio communication and satellite navigation during strong storms, not on people watching the sky. The real risks of aurora chasing are cold and traffic. See safety and clothing.

Can you hear the aurora?

Many people in the north have described crackling sounds. The aurora itself is too high for sound to reach the ground, but Finnish researchers have recorded sounds linked to geomagnetic activity that appear to originate only some tens of metres above the ground. Read more in myths and Sámi traditions.

When and where

When in the year can you see the aurora in Norway?

The aurora is there all year, but you need darkness. In northern Norway, bright nights and the midnight sun prevent aurora viewing from about mid-April until the beginning of September, according to the Norwegian Centre for Space Weather (NOSWE). The season is therefore the dark period from around September to early April. See the best time of year.

What time of night is best?

NOSWE says the aurora is usually best seen between 20:00 and 02:00, but that it is far from unusual outside that window. The most dynamic displays often come around magnetic midnight. Step outside and check several times during the evening. See the best time of night.

Where in Norway are the chances best?

At night the auroral oval typically lies along the coast of Troms and Finnmark, the two northernmost counties, and aurora is common there even when solar activity is low. Tromsø, Lofoten and Vesterålen, Alta and the rest of Finnmark are good bases. The coast has milder weather but often more cloud; inland is colder but often clearer. See Tromsø, Lofoten and Finnmark.

How often is there aurora in Tromsø?

According to NOSWE, statistically there is some kind of aurora over Tromsø every other night, ranging from very faint to very bright. Whether you actually see it depends mostly on the clouds.

Can you see the aurora in Oslo and southern Norway?

Yes, but it usually takes a geomagnetic storm that pushes the auroral oval south. During the G5 storm of 10 May 2024, the first in over 20 years, aurora was seen at unusually low latitudes. On nights like that, look north, low over the horizon, and use a camera. See the aurora in southern Norway.

Can you see the aurora in summer?

Not in northern Norway, because it is light all night. The aurora is still there, but it is drowned out by daylight and the midnight sun. From around the beginning of September the nights become dark enough again.

Can you see the aurora in the middle of the day?

Not on the mainland, but on Svalbard it is dark even at midday during the polar night. You can then see dayside aurora from the part of the auroral oval that lies on the day side of Earth. It is usually fainter than night-time aurora. See the aurora on Svalbard.

How far away can you see the aurora?

According to NOAA, bright aurora can be seen from as far as about 1000 km away under good conditions, because it is so high up. That is why you can see it low in the north from places south of the oval itself.

Forecasts, Kp and weather

What does the Kp number mean?

Kp measures how disturbed Earth's magnetic field is, on a scale from 0 to 9, calculated for three-hour periods. Kp 5 or more counts as a geomagnetic storm: NOAA calls Kp 5 G1 and Kp 9 G5. A higher Kp means the aurora can be seen further south. Read the Kp index explained.

What Kp do I need to see the aurora?

It depends on where you are. In northern Norway, which sits under the auroral oval, you can often see aurora at low Kp. The further south you are, the higher the Kp needed. Kp is a rough, global number, so treat it as a guide, not a guarantee.

How reliable are aurora forecasts?

The shorter the range, the better. NOAA's 30-minute forecast uses solar wind measured at the L1 point, about 1.6 million km away, and gives 30–90 minutes' warning. Kp forecasts several days ahead are far less certain. See how to read an aurora forecast.

Can you see the aurora through clouds?

No. The aurora is far above the clouds, so you need gaps in the cloud cover. The sky does not have to be perfectly clear, but thick cloud blocks everything. See clouds and clear skies.

Does the moon ruin my chances?

A bright moon, especially around full moon, lightens the sky and can outshine faint aurora. Strong aurora is still easy to see in moonlight. The same goes for town lights: drive out of town to see more.

Is solar maximum over, and does that mean less aurora?

Solar cycle 25 peaked in October 2024 in terms of the smoothed sunspot number, according to the SIDC in Belgium. We are now in the declining phase. NASA notes that fairly significant storms often occur during this phase too, and in northern Norway aurora is common wherever we are in the cycle. See the solar cycle.

Photos, clothing and the app

Why does my camera see more colour than my eyes?

Your eyes have two kinds of light-sensitive cells: rods, which are very sensitive but do not see colour, and cones, which see colour but need more light. In the dark we rely mostly on rods, so faint aurora often looks greyish-white. A camera sensor can gather light for several seconds and captures the colours. See aurora colours.

What should I wear?

Dress for standing still in the cold for hours: wool next to the skin, an insulating mid layer and a windproof outer layer, with spare mittens and socks. Read the full safety and clothing guide.

How does Nordlys i natt work?

The app combines NOAA's Kp forecast, cloud cover from MET Norway (the Norwegian Meteorological Institute) and how dark it is where you are, and gives one answer: JA (yes), KANSKJE (maybe) or NEI (no). Read more in how Nordlys i natt works, or check tonight's verdict for your location.

In short

To see the aurora you need three things at once: darkness, clear skies and enough activity. In northern Norway the activity is often sufficient, so cloud cover decides most nights. Further south you need a geomagnetic storm. Trust short-range forecasts over long-range ones, dress warmly, and step outside several times during the evening.