How do I know if I can see the Northern Lights?

A strong Kp-index score

One tool you can use to check out whether you might have a chance of witnessing the Northern Lights is to find out what the Kp-index is predicted to be. This figure, between 0 and 9, is displayed on the Icelandic Met Office’s aurora page. The Kp-index is a measure of geomagnetic activity in the Earth’s atmosphere and the stronger this is, the better the chance of seeing a good display.

Kp9 is the highest value and would indicate the likelihood of an exceptionally strong geomagnetic storm, but this is incredibly rare. Icelandic aurora hunters should look out for a figure of 5 or above; anything less than three is considered quiet and typically you won’t see much, if anything at all.

Another factor to consider is that winter might not be the best time for your aurora hunt. At certain times of year, the solar winds peak, making it more likely for you to see the Northern Lights in all their vibrant glory. Around the time of the spring and autumn equinoxes in March and September, stronger activity is much more common and so if the aurora borealis does make an appearance, the colours are often more intense.

The position of the aurora oval

Compared to some Nordic regions, Iceland is positioned at a comparatively low latitude – even the northern part of the mainland is below the Arctic Circle. This does bring with it the advantage that the winter weather in Iceland isn’t always as extreme as more northerly countries which is good news for those planning to stand outside for extended periods waiting for the aurora to show up.

The Northern Lights forms a giant loop around the Arctic, known as the aurora oval. The stronger the Kp-index, the further south this oval will stretch. Iceland usually falls within this oval, even if there’s relatively little solar activity. But note that you can also see an aurora that’s much further north if you have an unobstructed view, so positioning yourself with a clear line of sight on a cloudless night will help too.

To find out what’s happening with the aurora oval, check out the website of the National Oceanic and Atmospheric Administration (NOAA), a US scientific agency. It produces real-time maps showing the progress of the oval; the time is displayed in the bottom right corner. Because Iceland is such a distinctive shape, you should have no trouble in working out where the oval is in relation to the country.

A dark location

There’s no chance of seeing the Northern Lights in broad daylight. The late sunset and early sunrise of midsummer in Iceland means that summer is not aurora season. Early autumn and late spring can also present challenges, though so long as it’s dark enough, you have a chance. Somewhere sparsely populated like the Reykjanes peninsula is ideal in this respect.

Moonlight is not your friend, and if there’s a full moon during your Northern Lights hunt it’s going to wash out the colours. If the Kp-index is sufficiently strong, you will still see the aurora, however, so don’t be put off entirely. On such a night, it might even be helpful as you’ll be able to see the settings on your camera or phone more easily when you’re trying to set up a shot. If you’re keen to plan ahead, you can check the moon phases for Iceland here.

You can scope out potential locations using Google maps. However, if you’re on a self-led aurora hunt, you might wish to identify possible locations in person before nightfall. This means that if you plan to walk a short distance to where think you’ll wait for the Northern Lights, there’ll be less chance of stumbling on uneven ground if you’re familiar with the lie of the land and know of any tricky stretches.

Cloudless skies

One of the most frustrating aspects of any Northern Lights hunt is if the sky is swathed in thick cloud that masks the dazzling display that’s taking place above it. Iceland’s position in the mid-Atlantic gives it a maritime climate and it’s no stranger to cloud. That said, you only need a small break in the cloud and you might catch a glimpse. Patience is definitely important as conditions can change rapidly.

Weather forecasts are your friend and if you visit the Icelandic Met Office’s website there’s plenty of up-to-date, useful data to tap into. They produce a handy map showing the expected geographical spread of various types of cloud as well as a composite picture. Click the time at the bottom of the map and you can see how the clouds develop or thin over the course of the night.

What this means if you’re planning a self-drive hunt or thinking of booking a Northern Lights tour is that may need to travel a short distance to find a spot that’s cloud-free. Make sure you have mobile data and a fully-charged battery so you can keep an eye on the forecasts as the evening wears on.

The right time of night

This one’s a tricky one as the aurora can show up at any time of night. Most often, however, it makes an appearance within a few hours either side of midnight. But keep you eyes on the sky as you walk back from dinner, for instance, or prepare yourself for a bit of hanging around while you wait for them to show up later in the evening.

Some travellers prefer to attempt to see the aurora borealis from a single location, such as their hotel. It’s helpful to know that some properties offer a wake-up call so you can get some sleep – or at least stay in the warm – until the Northern Lights show up. If you plan to do this, scope out a potential viewing spot in advance and have your outdoor layers ready to pull on at short notice.

You might also consider booking a late slot for a soak at the Blue Lagoon. The opening hours of this geothermal spa vary according to the time of year. Typically, it opens until 10pm through some of spring and autumn and to 9pm in winter so you could potentially catch sight of the aurora from the pool.

As you can see, there is a wealth of information online to help you prepare for your Northern Lights hunt on the Reykjanes peninsula. But of course, the other thing you’ll need is luck. Even when it is visible, the aurora can dazzle for hours or fizzle out in minutes. But if the aurora borealis does make an appearance, this enchanting spectacle will be one of the standout moments of your trip. Now that’s worth doing a bit of homework for, right?