The aurora forecast that respects your time.
One honest verdict — GO or NO-GO — from activity, darkness, cloud and moon. We gate the alerts so you only get pinged when it's actually worth stepping outside.
Use the free app tonight, or speak to Jo about seeing the lights in person.
- ✓ No ads
- ✓ No account
- ✓ NOAA · Open-Meteo · NASA data
- ✓ Works offline
- ✓ Five languages
Strong chance after dark — clear skies, low moon.
How the verdict works
Activity × Darkness × Clear sky × Moon
= an honest GO / NO-GO. Darkness and cloud are hard gates — a brilliant aurora behind cloud scores near zero, exactly as it should.
A look inside
More than a number: the app tells you whether to go, when, and where to look — then helps once you're out in the cold.
Kp 4 building — keep an eye out.
Clear & dark — get ready to head out.
GO — look north, it's happening.
Look NNW
15° above the horizon
Field Mode · red lightIllustrative screens — the free app runs it live, wherever you are.
Thick cloud after dark — you'd see nothing.
How we calculate the score
When we say no, you're not missing anything.
The Tonight Score fuses four things — and two of them are hard gates:
- Darkness— hard gate; daylight or deep twilight scores zero
- Clear sky— hard gate; cloud is an opaque lid
- Moon— penalty; a bright moon dims faint aurora
- Solar activity— the engine; vital, but never enough on its own
A strong Kp over Tromsø means nothing if 95% cloud sits between you and the sky. So a no is a real no — and we won't ping you out into the cold for nothing.
Tonight Score
A gated, multi-factor go/no-go — not just a raw Kp number.
Viewability-gated alerts
Watch / Warning / Now — only when you can actually see it, with quiet hours.
Live compass + Field Mode
Where to look, and a red-light mode for your night vision.
Eyes vs camera
Honest expectations, so you're thrilled — not let down.
Photography assistant
Exposure calculator + shot log tuned to tonight.
Plan ahead
Dark-sky calendar, 3-night outlook and a trip planner.
Private by design
No account. No ads. No tracking. Runs on free public NOAA / Open-Meteo / NASA data. Five languages. Works offline.
Aurora forecasts are guidance only — the Northern Lights are natural, unpredictable and never guaranteed. The Tonight Score combines available space-weather, darkness, cloud and moon data, but conditions can change quickly and data can be delayed or incomplete. Always make your own judgement before heading out at night: check local weather, roads, access and safety advice, dress for the cold, and don't enter unsafe or remote areas unprepared.