Northern lights alerts
for the city you choose
We watch NOAA's Kp forecast, then check local darkness and forecast cloud cover for your selected city. If the sky window looks usable, you get an email — otherwise we stay quiet.
Free forever · No spam · Unsubscribe anytime
Choose your destination, then let the alert check the night-by-night conditions.
Current Aurora Conditions
Planning context
How the alert logic chooses when to email
Kp is only the first filter
A Kp 4 night can be excellent in Tromsø and irrelevant farther south. Alerts use the saved city threshold rather than a single global number.
Open related guide →Darkness matters
Midnight sun and twilight can suppress otherwise active aurora forecasts. The system checks whether the local sky is dark enough before sending.
Open related guide →Clouds decide usefulness
The email only goes out when the forecast looks actionable enough to justify stepping outside or moving to a darker viewpoint.
Open related guide →How It Works
Simple, automatic, and based on real science.
We monitor NOAA
Our system checks NOAA's Space Weather Prediction Center on the Kp forecast cadence, then looks for destination-specific alert thresholds.
We check local sky conditions
For your selected city, we suppress alerts when the window is daylight or the local cloud forecast is too blocked to be useful.
You get an email
We send an alert only when Kp, local darkness, and cloud cover line up near your selected city, with practical viewing guidance and destination links.
No hype alerts
Why we may stay quiet when Kp rises
A higher Kp number does not always mean your saved city has a useful viewing window. We only email when the forecast is relevant locally and conditions look reasonable enough to act on.
- ✓The Kp forecast rose, but not enough for your city threshold.
- ✓It is too bright outside: daylight, midnight sun, or strong twilight.
- ✓Forecast cloud cover makes viewing unlikely.
- ✓A similar alert was already sent recently.
- ✓Cooldown rules are active so we do not spam repeat alerts.
Sources: NOAA SWPC Kp forecast + Open-Meteo cloud forecasts. Alerts are planning signals, not promises: darkness, timing, location, and clear skies still matter.
What You Get
Subscribing gives you a practical night-by-night signal for the destination you chose — without treating every Kp spike as a reason to wake up.
- 🌌City-aware aurora alertsEmail only when your selected city clears its Kp threshold and the local sky forecast looks usable.
- 🌑Darkness filteringThe alert checks whether the local sky is dark enough, so midnight sun and bright twilight do not trigger false hope.
- ☁️Cloud-cover contextForecast cloud cover is part of the decision, because a strong Kp number is not useful under a blocked sky.
- 📍Destination contextAlert copy points you back to relevant destination and planning guides when a viewing window looks worth acting on.
Get Aurora Alerts
Free · No spam · Kp + darkness + cloud checks
Season first, alert second
Use alerts for tonight, not for choosing the month
Alerts are most useful after you have already picked a sensible aurora season and destination. For trip timing, compare darkness, weather, cold and cost first; then use live alerts to decide whether a specific night is worth going outside.
The Kp Index Explained
The planetary K-index (Kp) runs from 0 to 9 and is the standard measure of geomagnetic storm intensity. Our alerts use city-specific Kp thresholds, then filter for local darkness and cloud cover before emailing.
Very quiet geomagnetic conditions. Do not plan around aurora unless you are already in a high-latitude dark-sky area.
Faint aurora may be possible only close to the auroral oval, with dark skies and patience.
Some polar destinations can still see activity, but it is not a strong travel signal on its own.
Worth watching in strong aurora destinations such as northern Scandinavia, Alaska, Iceland and Canada if skies are dark and clear.
A good signal for many aurora destinations, but city threshold, darkness and local clouds still decide whether an alert is useful.
G1 geomagnetic storm. The aurora oval expands, so well-placed dark-sky sites farther south may become possible.
G2 storm. Strong displays are possible across many northern regions when timing and clouds cooperate.
G3 storm. Aurora can reach unusually low latitudes, though local darkness and weather still matter.
G4 storm. Major aurora outbreaks may be visible well beyond normal aurora destinations.
G5 storm. Rare extreme geomagnetic activity; aurora may be reported across very low latitudes.
Sources: NOAA Space Weather Prediction Center + Open-Meteo local cloud forecast · Updated every 3 hours
Frequently Asked Questions
How often will I get emails?
We only send city-aware alerts when the Kp forecast clears the threshold for your chosen place and the local forecast looks usable — dark enough, with cloud cover low enough to justify checking the sky. If Kp is low, it is daylight, or clouds look too blocked, we stay quiet.
What is the Kp index?
The Kp (planetary K) index is a 0–9 scale that measures global geomagnetic activity, published every 3 hours by NOAA's Space Weather Prediction Center. It's derived from 13 ground-based magnetometers around the world. Higher Kp = more aurora, visible at lower latitudes. We use Kp as the first filter, then check local darkness and forecast cloud cover before sending.
Where can I see aurora with Kp 5?
At Kp 5 (minor geomagnetic storm), the aurora oval expands significantly. You can expect visible auroras in northern Norway (Tromsø, Alta), all of Iceland, northern Finland and Sweden, most of Alaska, and northern Canada. With a really dark, clear sky, it may even be faintly visible in Scotland, northern England, and the northern US states.
Can I get alerts for a specific location?
Yes. Choose the city/destination you care about when subscribing. We only match subscribers to that selected city, use a stricter Kp threshold for places farther south, and suppress alerts when local darkness or cloud cover does not look usable.
Is this free?
Yes, completely free. We monitor NOAA's data around the clock and send alerts as a service to the polar travel community. You can unsubscribe at any time.
The next aurora could be tonight
Solar Cycle 25 has produced unusually active aurora conditions, but the useful question is still local: is it dark, clear enough, and active near your chosen city tonight? Sign up for free alerts and we will email when those signals line up.
Already watching the skies? Explore the best aurora destinations →