While northern lights are not rare at all, many things must come together in order for us to see them: You have to be in the right place at the right time.
“Where can I see them?”
Northern lights can be seen in an area around the north geomagnetic pole called the auroral zone. This zone includes for example the northern parts of Fennoscandia, Iceland, parts of Greenland, northern Canada, and parts of Alaska. Northern Norway in particular is a popular place to travel to see the aurora since even in the north, the coastal regions have relatively mild winter temperatures. Here, however, the cloud cover can often become an obstacle for seeing the aurora and some people prefer to travel a bit inland to get away from the clouds, even though the colder temperatures require a bit warmer equipment.
The region where the aurora occur in the north, i.e. the auroral oval, expands southwards as space weather conditions became stormier and geomagnetic activity increases, which means that aurora can be seen also further south. The so-called Kp index measures geomagnetic activity on a scale from 0 (low) to 9 (high). The map shows rough estimates of the southern border of the region in Europe where aurora can be seen during different Kp index levels. Estimates of the upcoming auroral oval position and the Kp index can be seen in the KHO auroral forecast. There is also a southern counterpart for the northern lights, but much fewer people there to see them since the southern auroral zone falls in the Antarctic and the surrounding ocean with no population. During times of high activity however, the aurora can sometimes be seen for example in New Zealand.
“When can I see them?”
While auroras occur throughout the year, the auroral zone lies far up in the North where the midnight Sun prevents us from seeing the aurora from around mid-April until the beginning of September. When planning for traveling to see the aurora, it might be a good idea to double check the rising and setting times of the Sun in the region you are planning to go to. Usually auroras can be seen best in the evening between 20:00-02:00, but it is not uncommon for them to appear outside this time window. The chart below shows an estimate of the best times for seeing the aurora in Tromsø, northern Norway. The red color shows times when it is generally too bright to see the aurora, while the yellow shows times when it should be dark enough but aurora are less common, and green is for when it is dark enough and aurora are more likely to occur. Statistically speaking there are some kind of auroras on every other night over Tromsø, but ranging from very faint to very bright.
Often the main obstacle for seeing the aurora is the weather, since the auroral light originates from far above the altitude where clouds are. Fortunately, the sky does not need to be completely cloudless in order to see the aurora, and sometimes it can even be an interesting addition to the view, especially when photographing the aurora.
“Are there some other things I should consider?”
Since any additional light sources can quickly outshine the aurora, one should venture away from cities or other places with strong light pollution. Additionally, it might be wise to consider the rising and setting times of the moon, especially during full moon, since it can often outshine the aurora.
“I am in Northern Norway on a cloudless January evening and it’s really cold. Do I have to stand out all evening not to miss out on the show?”
Fortunately, no. There are several things you can check online to see how likely it is that you will see some auroras. However, you might want to peep outside every now and then even if the websites show that there is nothing going on, just in case. In addition to the auroral forecast, there are several all-sky cameras available online (during the dark season) where you can actually see what is visible in the sky.
For more detailed information on the aurora, please see our page “What are the Northern Lights / Aurora?”