How to See the Northern Lights from the US

The northern lights (aurora borealis) are glowing curtains of light in the upper atmosphere, set off when charged particles from the Sun reach Earth’s magnetic field. Across most of the US they are an occasional treat rather than a nightly sight. Seeing them comes down to three things: a strong enough storm, darkness and a clear view to the north.

What the aurora is

The Sun sends out a steady stream of charged particles, the solar wind. NOAA’s Space Weather Prediction Center (SWPC) explains that the aurora grows brighter and spreads toward the equator when the solar wind speeds up and its magnetic field points southward, against Earth’s. The biggest displays follow coronal mass ejections (CMEs), huge clouds of gas thrown off the Sun. Moderate displays come from fast streams flowing out of coronal holes.

The light itself is produced about 60 miles up and higher. SWPC lists the colors by height:

• Green, the most common, comes from oxygen at about 80 to 250 miles up.
• Deep red also comes from oxygen, but only above about 180 miles.
• Purple edges come from nitrogen lower down, about 80 to 120 miles up. NASA adds that nitrogen also gives blue and pink light.

Reading the Kp index

The number you will see in every aurora forecast is Kp, a scale from 0 to 9 that measures how disturbed Earth’s magnetic field is. Each value covers a three-hour block of the day and is worked out from magnetometer readings around the world. Higher Kp means a bigger, brighter aurora that reaches farther from the pole.

SWPC’s rough guide goes like this:

• Kp 0 to 2: the aurora stays far north and is faint.
• Kp 3 to 5: it moves closer and brightens.
• Kp 6 to 7: it may be visible from the northern US.
• Kp 8 to 9: it may be overhead in northern states and seen much farther south.

NASA’s own guide is a little more hopeful, saying northern states can catch the aurora at Kp 4. Both can be right. The answer for any one place depends on its latitude, how dark it is, and how low you can see toward the northern horizon. At a modest Kp, the aurora may show only as a faint glow along the horizon, and a hill or a row of trees can hide it entirely.

Keep in mind that Kp is a planetary index, not a local forecast. It says nothing about your clouds or your moonlight.

The G-scale: storms by name

When Kp reaches 5, it counts as a geomagnetic storm, and NOAA labels it on its G-scale. The NOAA scales page also gives a rough idea of how far south each level has been seen:

G level	Kp	Name	Where the aurora has been seen
G1	5	Minor	High latitudes such as northern Michigan and Maine
G2	6	Moderate	As far south as New York and Idaho
G3	7	Strong	As far south as Illinois and Oregon
G4	8	Severe	Down to Alabama and northern California
G5	9	Extreme	Down to Florida and southern Texas

NOAA also lists how often each level occurs in an average 11-year solar cycle. Minor storms come about 1,700 times. Extreme ones come only about four times. NASA notes that Kp reached 9, the top of the scale, during the strong solar storm of May 10, 2024.

How our aurora pages use Kp

Our northern lights page takes the latest Kp forecast from NOAA and compares it with the level usually needed at each location’s geomagnetic latitude (latitude measured from the magnetic pole rather than the geographic one). When the forecast reaches that level during the night’s darkness, we call the aurora possible; one level below, we call it camera only. Each state page, such as Michigan, looks at that state’s prospects in more detail. The same check feeds the aurora line on every city page under tonight.

When and where to look

SWPC’s viewing tips are simple:

1. Get away from lights. City glow hides a faint aurora, and so does a bright Moon.
2. Find a clear view north. A hilltop or other spot with an open view north is ideal, because the aurora is usually lowest on the northern horizon from the US.
3. Go out near midnight. The best activity is usually within an hour or two of local midnight, roughly 10 p.m. to 2 a.m. In stronger storms the active hours stretch into the evening and the early morning.
4. Be patient. NASA notes that displays brighten and fade over the night. A quiet hour can turn into a lively one.

Before heading out, look at SWPC’s 30-minute aurora forecast. It uses solar wind measured about a million miles upstream of Earth, which gives roughly an hour’s warning, often less, of what is about to arrive. Forecasts further ahead are much less certain, because no one can measure a CME’s magnetic direction until it nears Earth.

Why your phone sees it better than you do

People are often surprised to find a vivid green or pink sky on their phone screen after seeing only a pale glow. There is a simple reason. In the dark, your eyes rely on rod cells, which are sensitive but can’t see color. SWPC notes that a dim aurora looks pale white to the eye, and colors show only when it brightens. A camera sensor collects light over several seconds and records color, and NASA points out it can catch an aurora you can’t see at all.

That makes your phone a useful test. If you think you see a pale band low in the north, take a photo. If it turns green or red on the screen, it’s almost certainly the aurora. Just remember that the photo exaggerates the color and brightness compared with what your eyes saw.

Photographing the aurora with a phone

Most recent phones have a night mode that takes a long exposure, or a series of short ones, and combines them. On iPhones it is called Night mode; Google Pixel phones call it Night Sight.

• Hold the phone still. Use a small tripod, or prop the phone on a rock, a car roof or a bag. A steady phone allows longer exposures. Google’s engineers wrote that Night Sight on the Pixel 4 can expose for up to four minutes in total, split into frames of no more than 16 seconds so the stars don’t smear into short lines.
• Use the timer so pressing the button doesn’t shake the phone.
• Turn off the flash. It will only light up the foreground.
• Tap to focus on a bright star or distant light, and lock it if your phone allows.
• Choose the longest exposure on offer, then shorten it if a bright, moving aurora looks blurred.
• Dim the screen, and use a red light so you keep your night vision.

Photographing it with a camera

With a camera, the basics are the same as for any night-sky photo: a tripod, a wide-angle lens, manual focus on a star, and a remote or self-timer to fire the shutter. Start with exposures of several seconds and adjust from there. A bright, fast-moving aurora looks better in short exposures, which keep the curtains sharp, while a faint glow needs longer ones. Our night-sky photography guide covers settings in more detail.

Cold drains batteries quickly, so carry spares in an inside pocket where they stay warm.