Northern Lights Forecast Tonight
This page shows the northern lights forecast for tonight in the United States, using live data from NOAA’s Space Weather Prediction Center. The headline number is the Kp index, a 0 to 9 scale of geomagnetic activity. At Kp 5 or higher (a G1 storm or stronger) the aurora can reach the northern states; the higher the number, the farther south it can be seen.
Tonight, highest Kp forecast
Kp 2.3
Where it may be visible
Alaska and northern Canada. In the lower 48, very unlikely.
Right now: estimated Kp 0.0 at 10:26 pm ET.
| Night | 10 pm | 1 am | 4 am | Max | |
|---|---|---|---|---|---|
| Thu, Nov 5 | 2.0 | 2.0 | 2.3 | 2.3 | |
| Fri, Nov 6 | 5.0 | 3.7 | 3.3 | 3.3 | 5.0 G1 |
| Sat, Nov 7 | 4.0 | 4.3 | 4.7 | 3.0 | 4.7 |
Data: NOAA Space Weather Prediction Center, updated Nov 5, 10:30 pm ET. Visibility areas are approximate and assume a clear, dark sky away from city lights. Short-term changes: NOAA’s aurora dashboard.
What does the Kp index mean?
The Kp index measures how strongly Earth’s magnetic field is being disturbed, based on readings from ground magnetometers around the world. NOAA reports it in 3-hour blocks on a scale from 0 (quiet) to 9 (extreme). A disturbed magnetic field pushes the auroral oval, the ring of light around the magnetic pole, toward the equator, which is why a higher Kp means people farther south have a chance.
| Kp | NOAA storm level | What it usually means for the U.S. |
|---|---|---|
| 0–3 | None | Aurora stays over Alaska and northern Canada |
| 4 | None (active) | Faint glow possible on the far northern horizon of the northernmost states |
| 5 | G1 (minor) | Low on the northern horizon along the Canadian border |
| 6 | G2 (moderate) | Visible across more of the northern tier |
| 7 | G3 (strong) | Can reach states such as Iowa, Illinois and Pennsylvania |
| 8 | G4 (severe) | Can reach the middle of the country |
| 9 | G5 (extreme) | Rare; may be seen far into the South |
How accurate is an aurora forecast?
A Kp forecast is a prediction of a storm that has not arrived yet. Most strong storms start with a coronal mass ejection, a cloud of solar material that takes one to three days to reach Earth, and the arrival time is often off by several hours. How strong the storm gets also depends on the direction of the magnetic field inside that cloud, which spacecraft can only measure about 15 to 60 minutes before it hits Earth. Treat the 3-night table as a heads-up and check NOAA’s 30-minute forecast on the night itself.
When and where should you look?
- Look north, from a spot with a low, open northern horizon and little light pollution.
- The best hours are usually within an hour or two of local midnight, roughly 10 p.m. to 2 a.m.
- Clouds matter as much as Kp: a G2 storm behind overcast skies shows nothing.
- Use a phone’s night mode. Cameras often record red and green that look gray or faint to the eye.
- Give your eyes 15 to 20 minutes away from screens and lights to adjust to the dark.
For the science behind the forecast, read how northern lights forecasts work, and for trip planning see where to see the northern lights in the U.S..