The Sun Is at Its Most Active in Over a Decade
If you have been waiting for the perfect moment to see the northern lights, 2026 is giving you one of the best windows in eleven years. The reason is Solar Cycle 25 — the ongoing 11-year cycle of the sun’s magnetic activity — which reached its peak in 2025 and continues to drive elevated geomagnetic conditions well into 2026.
During a solar maximum, the sun produces more solar flares, coronal mass ejections (CMEs), and high-speed solar wind streams. These energetic events travel 150 million kilometres to Earth, where they interact with the planet’s magnetic field and funnel charged particles toward the poles. The result is the aurora borealis — and right now, there is more of that energy reaching Earth than at any point since Solar Cycle 24 peaked around 2014.
What Solar Cycle 25 Has Already Delivered
Solar Cycle 25 has already proven to be more intense than scientists originally predicted. In May 2024, Earth experienced a G5-class geomagnetic storm — the most powerful in two decades — which produced auroras visible across large parts of North America and Europe. A G4-class storm followed in October 2024, and a further G4 event struck in November 2025.
For Iceland, storms of this magnitude mean full-sky aurora displays that extend well past midnight, with vivid curtains of green and sometimes red or purple light visible even from Reykjavik’s outskirts. Locations with darker skies — such as Þingvellir National Park or Kirkjufell Mountain — benefit even more, with the full structure of coronal arcs and dancing rays visible to the naked eye.
Why the Declining Phase Still Produces Strong Auroras
A common misconception is that once a solar maximum has passed, aurora activity drops off sharply. In reality, the years just after the peak are often the most unpredictable and intense for space weather. As the sun transitions from maximum toward minimum, its magnetic field becomes more complex and prone to sudden eruptions rather than steady elevated output.
This “declining phase” effect has been observed across multiple solar cycles. During Solar Cycle 23, for instance, some of the strongest geomagnetic storms occurred in 2003 — two years after the peak — producing the famous Halloween Storms. Scientists studying Solar Cycle 25 expect a similar pattern, with continued strong activity through 2026 before a gradual decline toward the next solar minimum around 2031.
That makes the window from now through late 2026 genuinely precious. After it closes, the next comparable aurora season will not arrive until approximately 2035.
How to Translate Solar Activity Into an Aurora Forecast
Understanding the solar cycle is useful context, but planning a specific night’s aurora viewing requires real-time data. Three measurements matter most:
- Kp index: A 0–9 scale measuring global geomagnetic disturbance. A Kp of 3 or above produces visible auroras in Iceland; Kp 5 and higher produces dramatic displays across the whole sky.
- Bz component: The north-south orientation of the solar wind’s magnetic field. A strongly negative Bz (below −10 nT) opens the Earth’s magnetosphere and dramatically amplifies aurora activity.
- Cloud cover: Iceland’s weather is the variable you cannot control. Clear skies over your location — not just low Kp — determine whether you see anything.
The live aurora forecast in the Aurora Iceland app combines all three in real time, scoring each viewing spot on a 0–100 scale based on OVATION aurora probability, actual cloud cover, and local darkness. During elevated solar activity, checking this forecast an hour before heading out can save a wasted drive — or reveal that the skies directly above Jökulsárlón Glacier Lagoon are clearing while Reykjavik stays overcast.
Practical Advice for the 2026 Season
Iceland’s aurora season runs from late August to mid-April, constrained by the need for genuine darkness. The summer months bring the midnight sun and no auroras at all; the winter months offer the longest dark windows. April sits at the tail end of the season — twilight grows longer each week, but strong geomagnetic events can still produce visible auroras on clear nights through mid-April.
If you are planning a trip specifically around the solar maximum, September through March gives you the best combination of dark nights and statistically reasonable weather. The equinox periods in late September and late March are particularly favourable: geomagnetic activity statistically increases around the equinoxes due to a phenomenon called the Russell-McPherron effect, which aligns the solar wind’s magnetic field more favourably with Earth’s.
For maximum flexibility, choose accommodation in the countryside rather than Reykjavik. Light pollution is the one factor you can control directly — moving even 30 kilometres from the city makes a measurable difference on nights when activity is moderate rather than exceptional.
Make the Most of a Rare Solar Window
Solar Cycle 25 has already produced aurora events that people in Iceland will remember for years. The elevated activity of 2025 and 2026 will not repeat itself until the mid-2030s. Whether you are planning your first trip or returning to Iceland specifically for the aurora, this season offers conditions that are genuinely rare.
Download the Aurora Iceland app to get real-time scores for 78 viewing spots across Iceland, or check the Tonight page for the current forecast at your location. When the Kp index climbs and the clouds part, you will want to move quickly — and having the data in your pocket makes all the difference.
