Aurora Forecast: When & Where to See the Northern Lights
The aurora is not magic — it is visible space weather. Learn to read the Kp index, understand what drives geomagnetic storms, and predict whether the lights will appear in your sky tonight.
On the night of May 10–11, 2024, people across the southern United States, central Europe, and even parts of Mexico and Florida looked up and saw something most had never witnessed: curtains of green, purple, and red light dancing across the sky. The strongest geomagnetic storm in 20 years — a G5 — had pushed the aurora oval deep into mid-latitudes. It was not a once-in-a-lifetime coincidence. It was predictable space weather, and you can learn to predict it yourself.
WHAT CAUSES THE AURORA?
The aurora borealis (Northern Lights) and aurora australis (Southern Lights) are caused by charged particles from the Sun — primarily electrons and protons — colliding with gas molecules in Earth's upper atmosphere at altitudes between 100 and 300 km. The collisions excite the gas molecules, which release energy as light when they return to their ground state. Different gases produce different colours.
●
GREEN AURORA
The most common colour. Produced by oxygen atoms at altitudes around 100–150 km. This is the wavelength the human eye is most sensitive to in low-light conditions, making it the most visible.
▸ OXYGEN · 100–150 KM · 557.7 NM
●
PURPLE / BLUE AURORA
Produced by nitrogen molecules at lower altitudes (below 100 km), often appearing at the lower edges of aurora curtains. Also seen during intense storms when particles penetrate deeper into the atmosphere.
▸ NITROGEN · <100 KM · 427–470 NM
●
RED AURORA
Produced by oxygen at very high altitudes (above 200 km). Rare and often difficult to see with the naked eye, but captured easily by cameras. Appears during strong geomagnetic storms.
▸ OXYGEN · 200–300 KM · 630 NM
THE KP INDEX — YOUR AURORA FORECAST NUMBER
The Kp index (planetary K index) is a global measure of geomagnetic activity, updated every 3 hours by NOAA's Space Weather Prediction Center. It runs from 0 (completely quiet) to 9 (extreme storm). For aurora viewing, it is the single most useful number to track — it directly determines how far from the poles the aurora oval extends and how intense the display will be.
VISIBLE: Central Europe, Pacific Northwest, Great Lakes
Kp7
G3 STORM
VISIBLE: Central US, southern Europe, New Zealand
Kp8
G4 STORM
VISIBLE: Southern US, Texas, Mediterranean, NZ North
Kp9
G5 EXTREME
VISIBLE: Florida, Cuba, Hawaii, tropics — May 2024
// HOW TO READ YOUR LOCAL KP THRESHOLD
A rough rule: aurora becomes visible at your location when Kp approximately equals (90 − your latitude) / 5. For example, at 55° latitude (Edinburgh, Scotland), aurora begins to appear around Kp4–5. At 40° latitude (New York, Rome, Beijing), you need Kp7+. At 30° latitude (Texas, Florida, southern Spain), you need Kp8 or higher. These are approximate — local light pollution, cloud cover, and solar wind conditions all affect actual visibility.
THE WORLD'S BEST AURORA VIEWING LOCATIONS
The aurora oval — the ring-shaped zone around the magnetic poles where aurora is most frequently visible — sits at roughly 65–72° geomagnetic latitude during quiet conditions. The locations below sit directly under or near this oval, giving them the highest number of aurora nights per year even at low Kp levels.
🇳🇴
TROMSØ, NORWAY (69.7°N)
Considered the world capital of aurora tourism. Sits almost directly under the auroral oval. The surrounding fjords and mountains provide dramatic foreground. Accessible aurora from September through March, averaging 200+ nights of geomagnetic activity per year. The Tromsø Geophysical Observatory has operated the world's longest continuous aurora record since 1839.
▸ MINIMUM KP FOR VISIBILITY: Kp1 · BEST SEASON: OCT–FEB
🇮🇸
REYKJAVIK REGION, ICELAND (64°N)
Iceland's position in the middle of the North Atlantic — under the auroral oval — and its low population density make it exceptional. No light pollution outside the capital. The Golden Circle, Snæfellsnes Peninsula, and the Westfjords are prime dark-sky sites. Weather is the main obstacle: overcast skies are common. Best to monitor forecasts hourly and be mobile.
▸ MINIMUM KP FOR VISIBILITY: Kp2 · BEST SEASON: SEP–MAR
🇨🇦
YUKON & NORTHWEST TERRITORIES, CANADA
Whitehorse and Yellowknife are two of the world's premier aurora destinations. Whitehorse (60.7°N) averages 200+ aurora nights per year. Continental climate means clearer skies than coastal Iceland or Norway. Yellowknife (62.5°N) markets itself specifically as the Aurora Capital of North America, with dedicated aurora chasing infrastructure.
▸ MINIMUM KP FOR VISIBILITY: Kp1–2 · BEST SEASON: OCT–MAR
🇫🇮
LAPLAND, FINLAND (68–70°N)
Finnish Lapland — Saariselkä, Inari, Utsjoki — lies inside the auroral zone. The Finnish Meteorological Institute provides one of the best national aurora alert services in the world. The low humidity and frequent clear skies of the subarctic continental interior make for excellent viewing conditions. The "Aurora Season" runs from late August to April.
▸ MINIMUM KP FOR VISIBILITY: Kp1 · BEST SEASON: AUG–APR
🇳🇿
STEWART ISLAND, NEW ZEALAND (47°S)
The aurora australis (Southern Lights) is less observed only because fewer people live at southern latitudes. Stewart Island, just south of the South Island, has minimal light pollution and a clear southern horizon. During G2+ storms, aurora australis is visible from southern New Zealand and Tasmania. G4–G5 events can light up as far north as Queensland.
▸ MINIMUM KP FOR VISIBILITY: Kp5+ · BEST SEASON: MAR–SEP
HOW TO FORECAST TONIGHT'S AURORA
Aurora forecasting has improved dramatically over the past decade. NOAA's DSCOVR satellite at the L1 Lagrange point provides 15–60 minutes of advance warning of incoming solar wind conditions. Here is the exact process professional aurora hunters use:
01
Check the 3-day CME forecast. NOAA SWPC publishes CME arrival predictions. If a CME is expected within 72 hours, there is potential for elevated activity. A confirmed southward Bz component in the CME makes it much more likely to drive a geomagnetic storm.
02
Monitor the real-time Kp index. Check NOAA SWPC (swpc.noaa.gov) or apps like SpaceWeatherLive. You want Kp above your location's threshold (see the scale above). The 3-hour estimated Kp updates continuously.
03
Watch the Bz component of solar wind. This is the most important real-time indicator. When Bz goes strongly negative (southward, typically −10 nT or lower), geomagnetic activity intensifies rapidly. DSCOVR data is available live on the NOAA website.
04
Check your local cloud forecast. Aurora happens above the clouds. A perfect G5 storm is invisible if it is overcast. Clear skies are non-negotiable. Check hourly cloud cover forecasts for your chosen location.
05
Get away from light pollution. Even a Kp6 storm can be washed out by a city's glow. Drive at least 30–50 km from urban centres. Your eyes need 15–20 minutes to fully dark-adapt after any bright light exposure.
06
Use a camera to see more. Phone cameras and DSLRs are significantly more sensitive to aurora than the naked eye, especially for red aurora at high altitudes. Even a 3-second exposure on a phone can reveal colours invisible to the eye. Always photograph on manual mode with ISO 1600–3200.
Aurora frequency and intensity follow the 11-year solar cycle. Solar maximum — the peak of sunspot activity — brings more solar flares, more CMEs, and therefore more frequent and intense geomagnetic storms and aurora displays. We are currently in Solar Cycle 25, which reached solar maximum in 2024 and exceeded all forecasts in its intensity.
// SOLAR CYCLE 25 — THE CURRENT WINDOW
Solar Cycle 25 began in December 2019 following a deep solar minimum. Its peak in 2024 produced the first G5 geomagnetic storm since 2003 (May 2024) and a series of X-class solar flares. The elevated activity is expected to persist through 2025 and taper into the next solar minimum around 2030. This is one of the best windows for aurora viewing at mid-latitudes in a generation — and Pandita Data's magnetic field simulations update in real time to reflect current solar wind conditions.