Start with the short-term map
Our map uses NOAA's OVATION aurora model. NOAA describes this product as a short-term prediction of auroral location and intensity, typically looking roughly 30 to 90 minutes ahead. Its lead time depends on the travel time of measured solar-wind conditions toward Earth. It is not an all-night weather forecast or a reservation for a particular display.
Find your location and check the model's timestamp. A forecast for an earlier interval is historical context, even if the colors still look convincing. If the feed is unavailable or outdated, treat the destination status as unavailable rather than assuming yesterday's conditions continue.
Read destination activity in context
A highlighted destination means the model reaches our activity threshold near that location. It does not mean somebody has confirmed a sighting there. The local values come from the forecast grid; they are not a cloud-adjusted, personalized probability that you will see the northern lights.
We smooth and lightly pad the map's colored regions to make the coarse forecast grid readable. A colored edge is therefore an approximate display boundary, not a precise line separating visible and invisible aurora. The destination readout is the better place to compare locations consistently. Around an edge, avoid drawing conclusions from a few screen pixels.
Use Kp for the bigger picture
Kp summarizes global geomagnetic disturbance on a scale from 0 to 9. Higher activity can expand the auroral oval toward lower latitudes, but Kp is not a local brightness meter. A promising global value does not answer whether clouds cover your horizon or whether an auroral burst is occurring over your town.
The three-day outlook helps identify periods worth monitoring. Use the short-term map nearer to the time you plan to look. Do not read a three-hour Kp interval as an appointment: displays can change within that interval, and a forecast value can differ from the value eventually observed.
Turn the forecast into a viewing decision
Work through a short sequence: confirm the data is recent, compare your destination with the modeled activity, check darkness, and check a local cloud forecast. Then choose an accessible viewing place with an open horizon. If the sky is clear and you are already nearby, looking outside may tell you more than repeatedly refreshing an index.
Keep your plans flexible. A modest forecast can still make an enjoyable night under the stars, while a stronger forecast can be hidden by a solid cloud layer. Save the detailed geomagnetic report for the questions it can answer; it cannot replace a local weather check.
Common questions
Does a 30% model value mean a 30% chance that I will see aurora?
No. Local visibility also depends on darkness, clouds, light pollution, viewing direction and the evolving display. Treat the model value as an activity signal, not a personalized seeing probability.
Why can the marker disagree with the edge of a colored region?
The overlay is smoothed and padded for readability, while the destination value is sampled from the underlying model. Near a boundary, a small difference is expected.
Sources & further reading
Start with these sources for the science and forecasting behind this guide.