Aurora tonight in Tromsø

Can you see the aurora borealis from Tromsø?

Tromsø sits close enough to the auroral oval that the northern lights are a routine winter occurrence rather than a special event.

Tromsø is the classic Arctic city aurora destination, and the reason is geography: the Gulf Stream keeps the harbour ice-free while the magnetic latitude sits at 66.7°N, so a display needs only Kp 2 to reach the northern horizon. That combination — warm enough to stand outside, far enough north to see the lights often — has no real equivalent at the same size elsewhere.

Country

Norway

Magnetic latitude

66.7°N

Geographic latitude

69.65°

Aurora threshold

Kp 2

Light pollution

Bortle 4

Deep-dark nights / yr

186

Sun at solar midnight

43.8° below horizon

Midnight sun

69 days

When to look: the Tromsø aurora season

Tromsø's deep-dark season runs from about **19 Sep** to about **23 Mar**: 186 nights a year on which the sun sits at least 18° below the horizon and the sky is genuinely black. Those dates come out of the city's latitude and longitude, not out of a regional generalisation. The counter-season is just as clearly defined: from about **24 Mar** to **18 Sep** (179 nights) the sun never gets 18° below the horizon, so the sky never reaches full darkness, and between roughly 9 Apr and 2 Sep it does not get properly dark at all — no display, however strong, is visible in that stretch.

Above the Arctic Circle, Tromsø gets about 69 days of midnight sun a year. The flip side is a midwinter night where the sun sinks 43.8° below the horizon — deep enough for a genuinely dark sky. Between those two extremes sits the practical aurora season, and the engine treats the bright end of that range as NO rather than raising false hopes.

Where to go in Tromsø

The city glow is the local obstacle, not the latitude. A short drive or even a walk west or north out of the centre puts you under noticeably darker sky, and any spot with open water toward the north gives you a low, uncluttered horizon.

Your viewing direction is fixed by Tromsø's position relative to the magnetic pole: look north, low on the horizon at first, and find somewhere that side is open and unlit. The "best window" figure above is simply the first hour tonight where cloud cover falls under roughly 40% while the sky is dark enough here to show anything.

What Kp do you need in Tromsø?

Kp is a planetary number, and the only way to read it usefully is against this city's own threshold. For Tromsø that threshold is Kp 2, set by a magnetic latitude of 66.7°:

The most common reason people miss a display at this latitude is timing rather than strength: a Kp 2 night is enough, but substorms come and go inside a single Kp interval, so a 20-minute gap in your attention can be the whole show. Check the sky every 20–30 minutes rather than once.

How tonight's answer is calculated for Tromsø

Five inputs produce the answer at the top of this page, and every one of them is specific to Tromsø: the NOAA Kp forecast against a threshold of Kp 2 (35% of the score), cloud cover through the night at 69.65°, 18.96° (25%), the moon (15%), astronomical darkness at this latitude (15%), and light pollution at Bortle 4 (10%). The scoring method, its inputs and its failure modes are written up in full on our methodology page. No account, no app, no email address — everything above is computed in your browser from NOAA and Open-Meteo data. Anonymous analytics and Google's advertising script are the only third parties involved, both explained on the privacy page.