Enter any location on Earth to see the next three nights' real aurora forecast — NOAA's Kp-index checked against your exact geomagnetic latitude, plus real darkness, moon phase, and cloud cover. Free, no account required.
By Robert Bridgewater · Last updated
Most aurora forecast pages show a single number — the Kp index — with no indication of whether it means anything for where you actually are. This tool combines four separate, genuinely real inputs for your exact coordinates, rather than one generic number.
Kp is a global geomagnetic activity index published by NOAA's Space Weather Prediction Center, updated every three hours and forecast a few days ahead. Higher Kp means the aurora oval has expanded further from the poles toward the equator. It's a real, physical measurement, but it's also a single global average — it doesn't know where you're standing.
The aurora oval is centred on the geomagnetic poles, not the geographic ones, and the two can differ by several degrees depending on where you are in the world. This tool converts your coordinates to an approximate geomagnetic latitude and looks up the minimum Kp historically needed for the oval to reach that latitude — the same reference table aurora chasers have used for years, just applied automatically to your specific location instead of a generic map.
Space weather forecasting is genuinely uncertain beyond about 30–60 minutes out — even professional forecasters revise Kp predictions as new solar wind data arrives. A location forecast to need Kp 6 can still get lucky with a sudden substorm on a Kp 4 night, and a “possible” night can just as easily disappoint if the expected activity doesn't arrive on schedule. Treat the three-night view here as your planning window, not a guarantee — and treat darkness, moon, and cloud cover as equally important, since a Kp 9 storm is invisible under full moonlight or thick cloud.
A strong Kp forecast is only half the picture. The sky needs to be properly dark (this tool uses real nautical twilight for your coordinates, not a fixed sunset time), the moon needs to not be washing out faint aurora structure, and the sky overhead needs to actually be clear — a perfect geomagnetic storm behind full cloud cover produces nothing to photograph.
A promising three-night forecast doesn't help if the best window opens at 2am on a work night, or if conditions shift after you've stopped checking. Real aurora activity can develop within a single check cycle.
Sudden substorms
Kp forecasts update every three hours, but real aurora activity can spike between updates — the forecast you checked at 8pm may already be out of date by 11pm.
Cloud gaps
A forecast showing high average cloud cover can still have a genuine clear gap for an hour — the kind of window that's easy to miss without an alert.
Moonset partway through the night
A night that looks marginal early on, with the moon still up, can become genuinely good once it sets — worth knowing about in real time, not just at a glance the evening before.
ShotScout's condition alerts are built to catch exactly this — watching Kp, darkness, moon, and cloud cover continuously for your saved locations, not just when you remember to check.
ShotScout's condition alerts are launching soon — join the early-access list to get them for your saved locations first.