Aurora Borealis in Soisy-sous-Montmorency, France Tonight
Aurora Borealis predictions for Soisy-sous-Montmorency tonight — updated every 6 hours
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30-Night Aurora Outlook for Soisy-sous-Montmorency
First 7 nights from data, remaining nights available in the app
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Aurora Borealis in Soisy-sous-Montmorency — What You Need to Know
Aurora Borealis & the Auroral Oval in Soisy-sous-Montmorency
Soisy-sous-Montmorency is located at 49.0°N, 2.3°E (geographic) and 50.5° magnetic latitude. This places it far from the auroral oval. The northern lights (aurora borealis) are only visible during extreme geomagnetic storms (Kp 9), requiring a minimum Kp index of 9.
In Soisy-sous-Montmorency, geographic and magnetic latitudes are close (49.0° vs 50.5°), so standard latitude gives a reasonable indication of aurora chances.
What is the Kp index?
The Kp index is a 0–9 scale that measures global geomagnetic disturbance. Higher Kp values push the auroral oval further from the poles — at Kp 3, aurora is common above 65° magnetic latitude; at Kp 7+, it can reach below 50°. A Kp of 9 means a G5 extreme storm — the most powerful category. These are rare (a few per solar cycle) but when they hit, aurora can be visible at surprisingly low latitudes.
Aurora Borealis Viewing Conditions in Soisy-sous-Montmorency
Even when the Kp index is high enough for Soisy-sous-Montmorency, several factors determine whether you'll actually see the aurora:
- Cloud cover — the single biggest obstacle. You need clear or mostly clear skies.
- Darkness — aurora is only visible when the sun is at least 6° below the horizon (civil twilight or darker).
- Moonlight — a bright moon (especially full) washes out fainter aurora displays. New moon nights are ideal.
- Light pollution — urban skyglow reduces contrast (Falchi et al. 2016). Getting even 15–20 km outside the city center makes a noticeable difference.
Best Time to See Aurora Borealis in Soisy-sous-Montmorency
In Soisy-sous-Montmorency, the best aurora viewing window is October through February, when nights are longest and darkest. While aurora can technically occur year-round, summer nights at 49° are too short and bright for reliable sightings. Watch for solar maximum years (roughly every 11 years) when Kp 9+ storms are most frequent.
Frequently Asked Questions — Aurora Borealis in Soisy-sous-Montmorency
Can I see aurora borealis in Soisy-sous-Montmorency tonight?
It depends on the current Kp index. Soisy-sous-Montmorency needs a Kp of 9 or higher for aurora borealis to be visible. Check the live forecast above for tonight's prediction, or download the Revon app for real-time alerts.
What Kp index is needed for northern lights in Soisy-sous-Montmorency?
Soisy-sous-Montmorency is at 50.5° magnetic latitude and requires a minimum Kp index of 9 for aurora to be visible. The Kp index is a 0-9 scale measuring geomagnetic activity — higher values push the auroral oval further from the poles.
When is the best time to see aurora borealis in Soisy-sous-Montmorency?
The best time to see aurora borealis in Soisy-sous-Montmorency is October through February, when nights are long and dark enough for observation. Within those months, the hours between 10 PM and 2 AM local time typically offer the best chances.
How does the aurora borealis forecast work?
The forecast combines NOAA solar wind and Kp index data with a machine learning model to predict aurora probability for each location. It updates every 6 hours on the website and every 15 minutes in the Revon app, which also factors in cloud cover, darkness, moonlight, and light pollution.