Aurora forecast: what Kp you need and where to see it

What Kp index do you need to see the northern lights?

There is no single magic number — the Kp index you need depends entirely on your latitude. The auroral oval sits permanently over the polar regions, and a geomagnetic storm temporarily expands it toward the equator. NOAA SWPC maps each Kp value to a rough boundary latitude and to its five-level G-scale (G1 at Kp 5 up to G5 at Kp 9). The table below shows roughly where each level becomes visible on a clear, dark night near the northern horizon.

A useful rule of thumb: each additional Kp point pushes the visible edge of the aurora roughly two degrees of latitude farther south. So if Kp 5 reaches your area's horizon, you typically need Kp 7–8 before the aurora climbs high enough to be obvious and photogenic.

Where can you see the northern lights tonight?

Whether tonight is your night comes down to the forecast Kp versus your location. Here is the rough threshold for the world's most popular aurora-chasing regions. Always check the live numbers before heading out — a forecast is a probability, not a promise.

Alaska and northern Canada

The easiest place on Earth to see the aurora. Under the auroral oval most clear nights, displays are common at just Kp 2–4. No storm required — you mainly need dark skies and clear weather between September and April.

Northern United States (Michigan, Minnesota, Maine, Washington, North Dakota)

The northern tier of the lower 48 needs a genuine geomagnetic storm. Expect a low-horizon glow from around Kp 5 (G1), with brighter, higher displays at Kp 6–7. Michigan's Upper Peninsula, northern Minnesota, North Dakota, northern Maine and the North Cascades of Washington are the sweet spots.

The UK and Scotland

Scotland and the Scottish islands catch the aurora from about Kp 5, often low to the north. Northern England and Northern Ireland usually want Kp 6, while the Midlands and southern England generally need Kp 7+ (a strong G3 storm or stronger).

Northern and central Europe

Northern Scandinavia (Tromsø, Abisko, Lapland) sees aurora regularly at Kp 2–3. Denmark, the Baltics and northern Germany typically need Kp 5–6, and central Europe — central Germany, Poland, the Netherlands — usually requires Kp 7+.

When and how to look

Timing and location matter as much as the Kp number. Follow these basics to give yourself the best chance.

• Wait for full darkness. The aurora is faint compared with daylight or twilight; aim for an astronomically dark sky.
• Target 10pm to 2am local time. Geomagnetic activity often peaks around local midnight, when your location sits on the night side of Earth facing the auroral oval.
• Get away from light pollution. City glow drowns out all but the strongest displays. Drive to a rural site with an open view.
• Face the northern horizon. In the northern hemisphere the aurora almost always appears to the north, unless a major storm brings it overhead.
• Let your eyes adapt. Give yourself 15–20 minutes in the dark; weak aurora often looks like a faint grey arc to the naked eye even when a camera reveals vivid color.

Plan around the data: check our Kp forecast for the next three days to pick the most promising night, and watch the live Kp index on the home page to know the exact moment activity spikes.

How to photograph the aurora

A camera gathers far more light than your eyes, so even a modest display can produce a striking photo. You do not need professional gear.

On a phone

Modern phones do remarkably well. Turn on Night mode (or a manual/Pro mode), set the longest available exposure — typically 3 to 10 seconds — and steady the phone on a small tripod, a wall or a rock. Any movement during the exposure blurs the shot, so use the timer or a voice shutter to avoid shaking the camera when you press the button.

On a camera

Shoot in manual mode with a wide, fast lens. A solid starting point is ISO 1600–3200, aperture f/2.8 or wider, and a shutter of 5–15 seconds — shorter when the aurora is moving fast, longer when it is faint and slow. Focus manually on a bright star, shoot in RAW, and lower the ISO if the highlights wash out.

The May 2024 Gannon storm

On 10–13 May 2024, Earth was hit by the strongest geomagnetic storm in over two decades — a G5 (Kp 9) event now known as the Gannon storm, named for space physicist Jennifer Gannon. It was the most intense storm since the 2003 Halloween storms and the most powerful since 1989.

The result was extraordinary visibility. According to reporting and scientific analysis, aurora was seen across the entire continental United States — as far south as Florida, Mexico, the Bahamas and Puerto Rico — and down to mid-latitudes across Europe, plus parts of Asia, Africa, South America, Australia and New Zealand. Millions of people who had never seen the northern lights photographed them from their backyards.

The lesson for aurora chasers is simple: big storms dramatically widen the visibility zone. When NOAA SWPC forecasts a severe (G4) or extreme (G5) storm, even people far from the usual auroral latitudes have a real chance — so it pays to watch the forecast closely during high solar activity.

Why is the aurora different colors?

Aurora colors come from charged particles from the Sun exciting gases in our atmosphere; each gas glows at a characteristic color, and the altitude of the collision matters too.

• Green — the most common color, produced by oxygen at altitudes of roughly 100–250 km. This is the bright, curtain-like green most people picture.
• Red — also from oxygen, but much higher up (above about 250 km), where the atmosphere is thinner. Red tends to crown the tops of strong displays.
• Blue and purple/violet — produced by nitrogen, typically at lower altitudes and along the lower edges of bright, energetic auroral curtains.

During powerful storms like the Gannon event, multiple colors appear at once, which is why those displays looked so vivid — and why cameras, which capture faint reds the eye can barely register, recorded such intense pinks and magentas.