Daylight in Finland and the Nordics

City	Country	Latitude	Longest day	Shortest day	Polar night	Midnight sun
Utsjoki	Finland	69.9°N	24h 00m	no sunrise	yes	yes
Tromsø	Norway	69.6°N	24h 00m	no sunrise	yes	yes
Kilpisjärvi	Finland	69.0°N	24h 00m	no sunrise	yes	yes
Saariselkä	Finland	68.4°N	24h 00m	no sunrise	yes	yes
Abisko	Sweden	68.3°N	24h 00m	no sunrise	yes	yes
Kiruna	Sweden	67.9°N	24h 00m	no sunrise	yes	yes
Levi	Finland	67.8°N	24h 00m	no sunrise	yes	yes
Rovaniemi	Finland	66.5°N	24h 00m	2h 14m	no	yes
Akureyri	Iceland	65.7°N	23h 30m	3h 04m	no	no
Oulu	Finland	65.0°N	22h 02m	3h 34m	no	no
Reykjavík	Iceland	64.1°N	21h 10m	4h 06m	no	no
Tampere	Finland	61.5°N	19h 30m	5h 20m	no	no
Turku	Finland	60.5°N	19h 04m	5h 44m	no	no
Bergen	Norway	60.4°N	19h 00m	5h 44m	no	no
Helsinki	Finland	60.2°N	18h 56m	5h 48m	no	no
Oslo	Norway	59.9°N	18h 50m	5h 52m	no	no
Stockholm	Sweden	59.3°N	18h 38m	6h 06m	no	no
Gothenburg	Sweden	57.7°N	18h 06m	6h 32m	no	no
Copenhagen	Denmark	55.7°N	17h 32m	7h 02m	no	no

The longest and shortest days are sampled on the 1st and 15th of each month and on the solstices, so a figure can be a minute or two off the true extreme. The polar night and midnight sun columns are not approximations: they are whether the sun fails to rise or fails to set at all on a sampled date.

Rovaniemi is the interesting one, and the table above says something most guides get wrong: it has the midnight sun and no polar night. The Arctic Circle is defined as the latitude where the sun just fails to rise at the winter solstice, but that definition ignores refraction, and the atmosphere bends enough light over the horizon that the sun does clear it here. Rovaniemi gets two hours and fourteen minutes of daylight on the solstice. In June the same effect works the other way and helps, so the midnight sun is real. The Circle gives you one of the two, not both. The first places on this list with genuine polar night are Levi, at 67.8°N, and Kiruna in Sweden, at 67.9°N.

For the aurora, daylight is not the number that matters; astronomical darkness is, meaning the sun more than 18° below the horizon. Rovaniemi has no astronomical darkness at all from late May to mid-July, even though the sun does set. That is why the aurora pages say "too light" in June on nights when the sun goes down at half past midnight.