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Three people watching the northern lights by Skjaldbreið mountain.
Photo: Photo: Golli. Three people watching the northern lights by Skjaldbreið mountain..

How to Read a Northern Lights Forecast

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The northern lights are a phenomenal natural occurance and some people make their way all the way to Iceland specifically to see them. Whether your one of those people, or simply think some aurora magic would be an ejoyable add-on to your vacation, the northern lights forecast can be a helpful useful tool. As any forecast, it’s not 100% reliable or accurate. Nature will do what nature does, and sometimes it’s not what we expected. However, the forecast is a decent indicator of whether you can expect to see some lights, how much, and where. Let’s take a closer look at what the northern lights are, how the northern lights forecast works, and how to read it.

What are the northern lights?

Before diving into the ins and outs of the northern lights forecast, let’s take a quick look at what the northern lights are. In short, the multicoloured lights we see dancing in the night sky and call the northern lights exist due to charged particles that originate from the sun. If they manage to break through Earth’s magnetic field, they collide with atmospheric gases which results in the gases being stripped of their electrons. The magic happens when these are recovered, and given the right conditions, we here on Earth are so tremendously lucky to be able to witness it.

But the right conditions are not always in place, which is why the norhtern light forecast can be a helpful guiding tool on our hunt.

The northern light forecast

On the Icelandic Met Office website, there’s a section called ‘Aurora forecast’. The forecast constitutes four parts: a cloud forecast, the time of sunrise and sunset, the time of moonrise and the moon phase, and a forecast of auroral activity. Together, these four components will give you a good idea of whether you can expect to see the northern lights or not. But how do you actually read the forecast?

Cloud forecast

Starting with the cloud forecast, you’ll see it on a big map of Iceland when you enter the Aurora forecast page. This maps tells you the predicted cloud covarage for the next three days. This is an important factor as mostly clear skies are necessary for us to see northern lights. You should, therefore, find a place where the sky is mostly or fully clear. On the map, coloured areas represent clouds while white areas represent clear skies. You can move back and forth in time by using the sliding bar at the bottom of the map.

Screenshot of the vloud forecast from the Icelandic Met Office.
Screenshot of the cloud forecast from the Icelandic Met Office. The forecast indicates nearly full cloud coverage in most places.

Level of brightness

Another necessary condition to see the northern lights is, of course, darkness. This is why autumn, winter, and spring are the best times to see them. During the summer months in Iceland, the sun is pretty much up 24/7. While it’s a phenomenal and highly reccommended experience, it doesn’t accommodate for northern light spotting.

To the right of the cloud map, there’s a box marked ‘Sun’, in which you can see the times of sunset and sunrise. If you’re not sure how those will impact the level of brightness, the box will also tell you whether it’s dark outside or not.

Below the ‘Sun’ box, you’ll see the ‘Moon’ box which tells you the time of the moonrise. There’s also an image of the moon which indicates which phase it’s in. Mild and low auroral activity might be difficult to spot with the bright light of a full moon, but if the activity is strong, it allows for better photography.

Screenshot of the 'Auroral Forecast', 'Sun', and 'Moon' boxes from the Icelandic Met Office.
Screenshot of the ‘Auroral Forecast’, ‘Sun’, and ‘Moon’ boxes from the Icelandic Met Office.

Auroral activity

The aurora forecast itself is a prediction of auroral activity at midnight each day. It is measured using the Kp index, which will give you a number on the scale from zero to nine. A zero indicates very low level of activity and a nine indicates extremely high levels of activity. A Kp index of 4 or higher is usually a sign of decent or very good northern light viewing but even on days when it’s lower, you might be lucky and spot some!

To summerize, the things you should be looking for in the forecast is a combination  of the following:

  • Areas with clear or mostly clear skies
  • Darkness
  • Higher levels of auroral activity

The best places to spot the norhtern lights

Northern lights can often be spotted within cities and towns, even the bigger ones like Reykjavík. It won’t be as strong as in the countryside, but you’ll still be able to see it! Popular places to see the northern lights in the capital include Grótta lighthouse on Seltjarnarnes, Grandi area and the Old Harbour, Perlan and Öskjuhlíð hill. For further information, check out our full guide on the best places to see the northern lights in Reykjavík.

Northern lights by Áskirkja in Reykjavík.
Photo: Golli. Northern lights by Áskirkja in Reykjavík.

That being said, there are few things as breathtakingly beautiful as a clear sky full of northern lights in the countryside and Highlands. The absolute silence of the wilderness and the overwhelming amount of stars visible lift the experience up to a whole other, nearly indescribable level. So, if you came to Iceland with the goal of seeing the norhtern lights, you can get a much better show if you go outside cities and towns where there’s less light pollution or none at all.

If you can’t or don’t want to drive, there are plenty of northern light tours awailable to book. They are dependent on weather conditions and will confirm in the afternoon of the day of the trip whether it’s on or not. Most will offer you a free second try if the first one doesn’t result in any northern light spotting. You can choose between a driven tour or a boat tour and some of them even include a hot chocolate, a welcome source of warmth during cold nights.

A jeep on a northern lights tour.
A jeep on a northern lights tour.

What not to do when looking for northern lights

This one might be obvious, but do not, under any circumstances, stop your car in the middle of the road to watch the northern lights. You should always find a place where you can safely park your car before turning. The roads in Iceland are usually quite narrow and often don’t have a big shoulder, so you might have to take some time to look for a good spot.

Equally, don’t stand in the middle of the road. Ideally, you should also use reflectors to enhance your visibility. If you don’t have reflectors, you can usually find them in gas stations, paharmacies, and even souvenier shops. Since they can be both useful and have an interesting design, these make for excellent memorabilia!

Don’t forget to dress warmly in layers: thermal underwear, a wool or synthetic sweater, a warm jacket, mittens, a warm hat, and a scarf. If it’s supposed to rain, wear water resistant clothing. Don’t wear cotton clothes, as those will not keep you warm if you get damp or wet.

Don’t go on a northern light adventure without checking weather and road conditions beforehand. As you’ve probably heard, the weather in Iceland can be unpredictable and change quickly, especially during fall, winter, and spring. And even in good weather, road conditions can often be less than ideal.

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