Free iPhone app
The aurora forecast app that answers, instead of handing you a Kp index
Norya crosses auroral activity, the clouds directly above you, real darkness, the Moon and the solar wind into a single score out of 100, for your position and the hour ahead. When a measurement is missing, it says so rather than showing a zero.
iPhone, iOS 18 or later. No account. The score is computed on device.
- No account, no sign-up
- The score is computed on your iPhone
- No ads, no trackers, no analytics
The problem
A Kp index is a measurement, not an answer
Most aurora apps put the Kp front and centre. It is a planetary index, published in three-hour blocks. It knows nothing about your latitude, nothing about the cloud deck above you, nothing about the Moon that is about to rise.
The question you actually ask at two in the morning, standing outside in the cold, is much simpler: is it worth staying out? Answering it means combining five things, not displaying one.
So Norya combines them. Auroral activity comes from NOAA’s OVATION model, 30 to 90 minutes ahead. The sky comes from three cloud layers, visibility and rain. Darkness is computed from how far the Sun has actually set. The Moon counts for its phase and its height, because a high full Moon erases a weak aurora. Solar wind is averaged over thirty minutes: Bz, speed and density.
The result is a score from 0 to 100, written "74 /100" and never "74 %". It is not a probability, and the app refuses to let you think it is.
What Norya puts on screen
Five screens, one scoring engine. The number on the home screen, the map, your favourites, the widget and the alerts is always the same number.
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Score, verdict and viewing window
The number set large, the verdict in two lines, the hour to go out, the three factors weighing most tonight, and the whole night as one chart.
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By day, the peak of the night ahead
At two in the afternoon the current score would be zero whatever happens, because the Sun alone cancels it. Norya shows the coming night’s peak instead, and labels it as such.
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Conditions, hour by hour
One card per hour with the forecast sky, cloud cover, score and temperature. Below, three scrubbable curves and the underlying measurements in full.
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The auroral oval on a globe
The live oval, the day and night terminator drawn as two lines, gold at sunset and blue at the start of real darkness, and your pinned places. Tap a point to query it.
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Your destinations side by side
As many saved places as you want, each with the local time there, the sky it has and its score. Tap a card and the home screen follows it.
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An alert when the sky opens up
Norya watches your place with the app closed and tells you when conditions cross your threshold. Confidence requirement and quiet hours are adjustable. This one is part of Norya Pro.
How you use it
Three moves, and the app answers for the place and the hour that concern you.
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Pick a place
Your own position, or any destination searched by name. Times shown are those of the place you are looking at, never those of your phone.
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Read the score and the window
A number, a plain verdict, a start time and a duration. Below it, the three factors that make that score tonight specifically.
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Go out at the right moment
With Norya Pro the app tells you by itself when the threshold you set is crossed, even if you never opened it that evening.
The app, screen by screen
Captured on one night in Tromsø during a G3 geomagnetic storm under a clear sky. The measurements are fabricated for the demo, the computation is not.
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Today: score, verdict, viewing window
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Hourly: the best window, then every hour
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Map: the auroral oval and the terminator
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Favourites: five destinations at a glance
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Conditions: cards, curves, measurements
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Alerts: threshold, confidence, quiet hours
The detail that lengthens your season
A darkness threshold built on measurements, not on habit
Most apps require astronomical night, meaning the Sun 18 degrees below the horizon. The number is convenient, but sky brightness measurements do not support it.
Between −18° and −12°, background sky brightness changes by a factor of 7. Between −12° and −6°, it changes by a factor of 400. The real break is not where the convention puts it.
Norya therefore sets its limit near −10°. In Tromsø that opens the season in late August instead of 20 September: a month gained at each end, on nights when the aurora is genuinely visible and other apps still show zero.
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0 to 100
the score, never a percentage
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30 to 90 min
the OVATION model horizon
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−10°
the darkness threshold used
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250
automated tests on engine and app
What the app refuses to do
Four rules that live in the code, not in a mission statement
No weather, no score. Not zero, not a neutral value. A zero would mean "no chance", which is not the same thing as "I do not have the data".
A fully overcast sky gives zero. No floor quietly letting 60 % of the score through under a solid stratus deck.
Two sources are never maximised together. Fresh OVATION stands alone; past 90 minutes the app fades toward the Kp fallback. When the two models disagree, confidence drops, the score never rises.
Times belong to the place you are looking at, never to your phone. Checking Tromsø from London shows Tromsø time.
Worth reading before you travel
Long pages, written from what the app actually computes.
What is free, what is paid
The free tier genuinely gets you to an aurora. It is not a crippled demo: the score, the map and today’s forecast cost nothing.
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Free
€0 forever
Enough to decide whether tonight is worth it, with no time limit.
- Score, verdict and best viewing window
- 24-hour forecast
- Map, auroral oval, terminator
- Clouds, visibility, wind, Moon, Sun
- Kp, Hp30, Bz, Bt, speed, density
- NOAA three-day forecast
- As many saved places as you want
- The Lock Screen widget
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For one trip
15-day pass
€2.99 once
Norya Pro for fifteen days. Not a subscription: it stops on its own, there is nothing to cancel.
- Everything in Free
- Alerts with the app closed
- 72-hour forecast horizon
- The map timeline
- Detailed solar wind curves
- Every window of a night
- Comparison with the previous night
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Norya Pro
€3.99 per month, or €24.99 per year
For a season you follow closely, from the first autumn night to the last spring one.
- Everything in the 15-day pass
- The trend for the weeks ahead
- A calendar of the best nights coming
- Auto-renewing, cancel from iOS settings
App Store prices are authoritative and vary by country. Subscriptions are managed and restored from your App Store account settings.
Privacy
There is no account, so there is nothing to know about you
No sign-up, no email address, no password, no name. The app does not know who you are and has no way of finding out. The score is computed on your iPhone, your places stay there, and uninstalling erases everything.
No analytics at all. No TelemetryDeck, no Firebase, no Sentry, not even a launch counter. The developer does not know how many screens you open, or which ones.
One thing leaves your phone, and only if you turn alerts on: a randomly generated device id, Apple’s notification token, the coordinates of the place being watched and your thresholds. That is the whole list. One button in settings erases all of it, server side included.
Frequently asked questions
The questions people actually put to Google about northern lights apps.
Is there a tracker for the Northern Lights?
How do I get notified when the Northern Lights are visible?
What is the best weather app for tracking the Northern Lights?
Is the aurora app free?
Does Norya work without a connection?
Which devices does Norya run on?
Where does Norya get its data?
The next clear night might be this week
Norya is free, asks for no account, and will tell you plainly on the evenings when it does not know.
Download on the App Store