Aurora tonight in Trondheim

Can you see the aurora borealis from Trondheim?

Trondheim sits south of the routine aurora zone, where the lights arrive only when geomagnetic activity pushes the oval far enough south to reach it.

Trondheim needs Kp 3. It sits on the coast at magnetic latitude 63.4°N, which puts it south of the routine aurora zone: displays here are events rather than background, but they are far from rare across a winter, and the long dark evenings give you plenty of chances to catch one.

Country

Norway

Magnetic latitude

63.4°N

Geographic latitude

63.43°

Aurora threshold

Kp 3

Light pollution

Bortle 5

Deep-dark nights / yr

219

Sun at solar midnight

50° below horizon

Midnight sun

none

When to look: the Trondheim aurora season

The dates worth planning around at Trondheim are **3 Sep** to **9 Apr**. Inside that run the sun clears 18° below the horizon on 219 nights and the sky is dark enough for a faint arc to register; outside it you are relying on twilight and luck. The counter-season is just as clearly defined: from about **10 Apr** to **2 Sep** (146 nights) the sun never gets 18° below the horizon, so the sky never reaches full darkness, and between roughly 27 Apr and 15 Aug it does not get properly dark at all — no display, however strong, is visible in that stretch.

The dark half of the year at Trondheim delivers a genuinely black sky, with the sun 50° below the horizon at its deepest. The bright half is the trade-off: from around 10 Apr to 2 Sep the sun stays above 18° below the horizon, and nothing short of a major storm has a chance.

Where to go in Trondheim

The city is low and spread out, so the light dome reaches a long way. Head out along the fjord or up into the surrounding hills for a horizon that is not lit from below.

Everything you are looking for is in the northern sky over the magnetic pole, so the practical requirement is simple: an unobstructed northern horizon with no artificial light in your line of sight. The "best window" shown above picks the first hour where cloud cover drops under roughly 40% while the sky here is genuinely dark.

What Kp do you need in Trondheim?

The table below converts the abstract Kp index into what it actually means from Trondheim, using its magnetic latitude of 63.4° and threshold of Kp 3:

At Trondheim two conditions have to hold at once — roughly Kp 3 of geomagnetic activity, plus a clear sky. The three-hour Kp figure hides a lot of variation: substorms can deliver a bright ten minutes inside an otherwise quiet interval. If the verdict above reads MAYBE, the geomagnetic side is usually not the problem; cloud is.

How tonight's answer is calculated for Trondheim

Five inputs produce the answer at the top of this page, and every one of them is specific to Trondheim: the NOAA Kp forecast against a threshold of Kp 3 (35% of the score), cloud cover through the night at 63.43°, 10.40° (25%), the moon (15%), astronomical darkness at this latitude (15%), and light pollution at Bortle 5 (10%). How the score is built, where the numbers come from and where the method can go wrong are all set out on our methodology page. There is nothing to install and nothing to sign up for: the calculation runs in your browser against NOAA and Open-Meteo. The only third parties are anonymous analytics and Google's ad script — our privacy page lists what each one does.