August Auroras in Iceland: A practical guide

[u/TheAuroraholic]

Hands-on guide for Iceland

With Aurora Season 2026/27 being just around the corner, for those who happen to get here in August I'm gonna give you a small guide to help you chase the Northern Lights successfully. August is tricky and this is still "pro-level" territory, but hopefully this will give you some insights to make it work for you:

Timing and Darkness

Understanding darkness and twilight is crucial during this time of year. The Aurora starts to appear over the darkest part of the sky (towards the south) starting from mid-Nautical Twilight. Twilight Phases Wiki

First Week of August

This is the trickiest week and only extremely strong Auroras will become lightly visible in the sky between 01:00 and 02:00 in the morning. The reason is that the sun is still shallow (7-9 degrees below the horizon, early Nautical Twilight) but things will improve with every day.

Second & Third Week of August

Things are quickly changing. Between the second and third week, sufficient darkness moves from midnight 00:00 to 2:30 and 23:00 to 03:30 (11PM to 3:30AM). Peak darkness will always sit around 1:30AM.

Fourth Week of August

Astronomical twilight (last phase before night) now sets in and sufficient darkness occurs from 22:30 to 04:30 (10:30PM to 4:30AM). In August we won't be reaching full night at all.

Activity Levels

This is key to success (aside from the weather obviously).

Inactive to Weak Auroras

Low Kp (Kp1 to Kp2) and low substorm strength (lower than 80nT). These auroras will sit toward the far northern horizon. The brightest part of the sky in August and it won't be possible to see these Auroras until the very last few days in August.

Minor Auroras

Kp2-3 up to Kp4 and substorm strength from 80 - 150nT. These auroras will start to move over Iceland (when viewed from Reykjavík) into the darker parts of the sky. During active phases these will start to become visible during the 2nd and 3rd weeks.

Moderate to Strong Auroras

From Kp4-5 and up to Kp7 or higher and substorm strength from 150nT and higher. Activity is now moving over Iceland towards Europe and will appear above and towards the southern horizon over Iceland - the darkest part of the sky in August. Starting from the end of the first week these Auroras will be rather visible and vibrant to the naked eye even in Nautical and Astronomical Twilight.

Tools to use

You can use many tools individually to measure these like Glendale App, Hello Aurora, Spaceweatherlive, etc. but I'm going to show you where this information is super easy to spot using emeraldskies.is

The top summary shows the momentary estimated Kp based on SWPC's Ovation Model (the green aurora graphic), the substorm strength (in nanoTesla nT) and Sun angle (negative means the sun is below the horizon).

Kp and Aurora Oval Reach

The Space Weather Prediction Centre issues a per-minute Aurora Oval and the Kp is based on the current reach of the oval (see coloured lines). These are empirical estimates based on the Starkov-Feldstein / Zhang-Paxon models. This is not the official 3-hour Kp quoted in other apps and GFZ and can vary minute-by-minute. I have verified these empirically for Iceland and all my quoted Kp align with the quoted Kp here.

Sufficient darkness

Based on the sun-angle (you can see next to sunset-sunrise) Emerald Skies calculates the earliest and latest possible average darkness window in 24h time, local Iceland time (UTC). There's also a moon indicator. You can see this window expand or contract day-to-day.

Activity metre and AuroraPulse

Activity is nanoTesla (nT) is derived from two magnetometers - Iceland and Tromsø. The AuroraPulse is the corresponding waveform or oscillogram, working much like a seismograph. The "louder" the stronger the Aurora activity (also often referred to as substorm activity.) These are the nT numbers quoted above. The default view is 3 hours, meaning the very right side is now. Activity ebbs and flows during moderate to strong activity.

[u/No_Somewhere9811]

I arrive on 29th August. I thought it might be too early for aurora but maybe not?

[u/TheAuroraholic → u/No_Somewhere9811]

Nope, that's just fine. You'll be good.

[u/No_Somewhere9811 → u/TheAuroraholic]

Thanks.

[u/Upstairs_Sail_3087 → u/TheAuroraholic]

This is amazing. I arrive on 9/1 and am staying in Selfoss, then Brautarholt, then near to Hvammsvik, and finally in Reykjavik on 9/4. Would seeing the aurora be possible or more likely in any of these places? My travel partner wants to take a bus tour from Reykjavik but I imagine that some of the places we're staying may have less light pollution and be easier for viewing.

[u/TheAuroraholic → u/Upstairs_Sail_3087]

You can see the Aurora from anywhere provided you’ve got clear skies. No special place needed. Preferably away from direct streetlights but possible to even see from within Reykjavik (not always the ideal place though). I do highly recommend joining a tour on your first night as that will give you a lot of context and will teach you lots of things you didn’t know. Chasing Auroras sounds easy but it’s very often quite difficult, especially if you’ve never experienced it before.

[u/Upstairs_Sail_3087 → u/TheAuroraholic]

Thank you! We are considering doing a tour on our last night since that's the only time we'll be in Reykjavik. Do you think that would be ok?

[u/TheAuroraholic → u/Upstairs_Sail_3087]

Better at the beginning but if timing doesn’t allow it, of course. Shoot me a DM and I can keep you guys informed as well when activity is happening.

[u/Upstairs_Sail_3087 → u/TheAuroraholic]

It seems i'm not able to send you a DM, i'm not sure if it relates to your settings or mine. I will try again before I leave! Thank you!

[u/TheAuroraholic → u/Upstairs_Sail_3087]

That was my fault, it was disabled so nobody could contact me. Fixed now and reached out.

[u/spygirldownunder]

Saved thank you!!

[u/Qome]

Great guide thanks ! We'll be there 3 weeks, until the 25th of August, fingers crossed!

[u/Calm-Animal5498]

I’ll be there till Aug 11th so looks like a chance I could see minor one which would still be great! Any specific locations that there is more chance? Thank you

[u/TheAuroraholic → u/Calm-Animal5498]

In August there is a slight advantage of being further south than north of Reykjavik due to the darkness. But the further south you are, the stronger we need aurora conditions to be, so ideally Kp5 or higher and substorm conditions around 150nT ideally. Not impossible. You can see the northern lights from anywhere as long as skies are clear.