The only aurora forecast that checks the clouds too. We combine the aurora forecast with your local cloud cover, so you're not left guessing whether you'll actually see it. Enter your zip code below.
If terms like "Kp" or "CME" mean nothing to you, this is the two-minute version of what's actually happening above your head.
The sun constantly streams charged particles out into space, called the solar wind. When those particles reach Earth, our planet's own magnetic field funnels them down toward the poles, where they collide with oxygen and nitrogen in the atmosphere and make them glow. That glow is the aurora.
Sometimes the sun erupts and hurls an enormous cloud of magnetized plasma out into space. If that cloud happens to be aimed at Earth, it slams into our magnetic field roughly a day or two later, sharply increasing the number of particles funneling toward the poles, and a much stronger, more widespread aurora.
A coronal hole is a cooler, darker patch in the Sun's outer atmosphere, called the corona, where the magnetic field opens up and lets a steady stream of fast solar wind escape continuously. Unlike a CME's single burst, these streams can affect Earth for several days, and often repeat roughly every 27 days as the sun rotates.
Kp is just a simple 0–9 scale for how disturbed Earth's magnetic field is right now. Low numbers (0–2) mean quiet, calm conditions, and the aurora usually stays confined near the poles. High numbers (5 and up) mean a geomagnetic storm is underway, and the aurora can be seen much farther from the poles than usual.
Seeing the aurora requires enhanced geomagnetic activity and clear sky overhead at your location, so we make sure to check both forecasts.
That's it, no account needed to check tonight.
Space weather and cloud cover, checked together instead of separately, the way every other aurora app leaves you to do yourself.
One percentage, not a chart full of numbers you'd have to interpret on your own.
Every confidence score is built from two independent readings so you can see exactly why tonight looks good, or doesn't.
Analysts at NASA's Moon to Mars Space Weather Analysis Office (M2M SWAO) track coronal mass ejections and model whether each one is headed for Earth. The tables below represent potential Earth-directed events that could enhance geomagnetic activity and lead to stronger northern lights. These are predictions, not certainties: CMEs regularly arrive early, arrive late, arrive weak, or miss Earth entirely. A CME that hasn't arrived yet simply doesn't move the needle as the Kp stays at background levels.
No daily digest, no spam, just a heads-up when a significant CME is inbound. Unsubscribe anytime.
No proprietary weather models, just the same government sources scientists use, translated into one plain-language answer.
It's a probability, not a guarantee. Geomagnetic storm forecasts depend on modeled coronal mass ejections that can arrive late, weaker than predicted, or miss Earth entirely. The confidence score reflects that uncertainty rather than hiding it.
Naked-eye visibility means the aurora should be visible to the eye. Camera-only visibility means a long-exposure camera can pick up aurora activity, usually as a faint reddish or greenish glow, even when it isn't visible to the eye, and it extends noticeably farther from the pole than naked-eye visibility does.
Aurora visibility tracks magnetic latitude, not straight geographic latitude, and the magnetic pole is offset from the geographic pole toward northern Canada. That's why, at the same Kp index, aurora is visible farther south over North America than over Europe at a similar geographic latitude.
The Kp index simply stays at background levels and the elevated forecast quietly doesn't happen. That's a normal outcome of CME forecasting, not an error, which is why confirmed current Kp and CME-dependent outlook are always shown separately.
Yes. Geomagnetic forecasting is global. Cloud forecasts use the National Weather Service inside the United States and a global weather source everywhere else, including Canada, Iceland, Norway, Sweden, Finland, and the UK.