Aurora season: when you can see the northern lights
Three things are necessary to see the aurora: a good level of solar activity, a clear sky, and darkness. Solar activity goes on all year round, regardless of the season. A clear sky could also be on any night of the year. Thus, we must answer the question: when is it dark enough for the aurora to be visible in the sky?
Faint aurora at the beginning of the season in Lapland
Usually, the aurora becomes visible when the sun is about 10° below the horizon. In this darkness, you can already see not only a few brightest stars but tens of them above your head. But it's still brighter than under the full moon. The sun is above that level in the polar regions for several months, between April and August. It means that even when the northern lights are dancing in the sky, you can't see them because it's too bright.
Of course, south of the latitude 56.5°N, the sun is lower than 10° below the horizon on any night of the year. But at that latitude, you can see the aurora only when the solar activity is very high, with one exception, I think. But about it later.
When it's dark enough in some popular aurora regions:
Canada, Churchill 17 July - 26 May
Canada, Whitehorse 27July - 16 May
Canada, Yellowknife 3 August - 9 May
Iceland, Reykjavik 9 August - 3 May
Alaska, Fairbanks 11 August - 1 May
Finland, Rovaniemi 18 August - 25 April
Finland, Levi 22 August - 21 April
Sweden, Kiruna 22 August - 21 April
Norway, Tromso 27 August - 16 April
But avoid the first and last weeks
It's important to mention that you can see only the faint aurora in the sky at the season's beginning and end. And it's only in the middle of the night. Photographing the aurora from the start of the season could be very tempting. But from the photography perspective, I recommend waiting a week or two for darker and longer nights.
Year-round aurora regions
Thanks to the geomagnetic pole position, there is a beautiful country where you can see the northern lights throughout the year. And you don’t need a very high level of geomagnetic activity for that. It’s Canada. For example, you can find breathtaking landscapes in Banff and Jasper national parks in Canadian Rockies and photograph the aurora even with Kp3-Kp4. You can also find beautiful year-round aurora locations in the southern part of Ontario, Quebec, and the northern part of Minnesota. When the geomagnetic activity is higher (Kp 5-6), you can add New Zealand, Tasmania, Ireland, the northern part of the US, Denmark, the UK, and Lithuania to the list.
