Aurora Forecast Tonight in Portrush
Aurora season in Portrush runs from September to April.
Tonight's Forecast
Low
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How we calculate the aurora score
LowWe combine geomagnetic activity (Kp), aurora oval probability (OVATION), cloud cover, darkness and moonlight, weighted for Portrush (region: mid_latitude).
Score 0–19. Conditions strongly limit aurora visibility.
Score 20–44. A faint aurora is possible only under perfect conditions.
Score 45–64. Aurora may be visible to alert observers in dark, clear skies.
Score 65–84. A good chance of a visible aurora display.
Score 85–100. Excellent odds — plan to be outside tonight.
Low chance tonight. Aurora may be possible only under very favorable local conditions.
Aurora activity may be favorable near Portrush, but cloud cover could make the Northern Lights difficult or impossible to see.
Max Kp
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Max Kp
Enough for this locationKp meets the threshold for visible aurora here.
5.7
Enough for this location
Cloud Cover
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Cloud Cover
OvercastOver 85% cloud — aurora effectively hidden.
100%
Overcast
Moon
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Moon
Dark moonLess than 25% illuminated — minimal interference.
4%
Dark moon
OVATION
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OVATION
LowLess than 5% probability — aurora unlikely to reach this location.
0%
Low
Best Viewing Window
10:00 PM – 12:00 AM
Best balance of darkness, geomagnetic activity and local sky conditions.
Direction to Look
North
At this latitude, aurora is usually seen toward the northern horizon.
Recommendation
Cloud cover is the main problem tonight. Wait for breaks in the clouds before going out.
Hour-by-hour visibility
Estimated aurora visibility score for each hour of tonight at Portrush.
42
10:00 PM
42/100Max Kp
5.7
Cloud Cover
100%
Moon
4%
OVATION
0%
42
11:00 PM
42/100Max Kp
5.7
Cloud Cover
100%
Moon
4%
OVATION
0%
12:00 AM
20/100Max Kp
3.0
Cloud Cover
100%
Moon
4%
OVATION
0%
1:00 AM
20/100Max Kp
3.0
Cloud Cover
100%
Moon
4%
OVATION
0%
Best viewing window: 10:00 PM – 12:00 AM. Peak around 10:00 PM with a visibility score of 42/100.
Why this forecast?
There is a low chance of visible aurora tonight. Some conditions may help, but overall the forecast does not strongly support visibility.
Score breakdown
How tonight's aurora score for Portrush breaks down into activity and visibility components.
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Geomagnetic activity
22 / 40Geomagnetic activity (Kp 5.7) contribution to the score.
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Aurora oval probability
0 / 20OVATION aurora oval probability (0%) contribution.
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Cloud cover
1 / 20Cloud cover (93%) contribution — clear skies score full points.
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Darkness
15 / 15Sky darkness contribution — astronomical darkness scores full points.
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Moonlight
5 / 5Moon illumination (4%) contribution — new moon scores full points.
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Geomagnetic activity (Kp index)
Enough for this locationKp measures how disturbed Earth's magnetic field is on a 0–9 scale. Higher Kp pushes the aurora oval toward the equator. Portrush needs Kp ≥ 5.5.
Kp is below the minimum needed at this latitude.
Kp is close to the minimum needed — a faint aurora may appear low on the horizon.
Kp meets the threshold for visible aurora here.
Kp is comfortably above the local threshold.
Storm-level Kp ≥ 5 — aurora can be seen far south of its usual zone.
Enough for this location
Geomagnetic activity is only marginal for Portrush: expected Kp is 5.7, while this location usually needs around 5.5.
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Cloud cover
OvercastAverage cloud cover during the best viewing window. Clear skies are essential — even thin overcast hides the aurora.
Up to 25% cloud — excellent visibility.
25–50% cloud — aurora may peek through gaps.
50–85% cloud — most of the sky is blocked.
Over 85% cloud — aurora effectively hidden.
Overcast
Cloud cover is high tonight, which can block the view even if aurora activity is present.
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Sky darkness
Astronomical darknessAurora is faint and needs a dark sky. Astronomical darkness (sun more than 18° below horizon) is ideal.
Sun stays above 6° below horizon all night — no aurora-friendly darkness.
Sun 6–12° below horizon — too bright for faint aurora.
Sun 12–18° below horizon — sky is dark but not fully astronomical.
Sun more than 18° below the horizon — fully dark sky.
Astronomical darkness
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Moon illumination
Dark moonA bright moon washes out faint aurora colours. New moon is ideal; full moon hides everything but the strongest displays.
Less than 25% illuminated — minimal interference.
25–75% illuminated — faint aurora may be washed out.
Over 75% illuminated — only strong displays will be visible.
Dark moon
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Aurora oval probability (OVATION)
LowNOAA's OVATION model estimates the chance of aurora visible overhead within a 250 km radius of you.
Less than 5% probability — aurora unlikely to reach this location.
5–20% probability — aurora possible.
20–40% probability — aurora likely if skies are clear.
Over 40% probability — aurora very likely overhead.
Low
The aurora oval probability is low for this location tonight.
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Aurora zone
Fair zoneHow favourable Portrush's latitude is for aurora viewing in general — independent of tonight's conditions.
Lower latitude — aurora is rare and requires a major storm.
Mid-latitude — aurora visible only during moderate-to-strong storms.
High-latitude region — aurora is visible on most active nights.
Directly under the auroral oval — aurora is a regular occurrence.
Fair zone
Portrush is in an occasional aurora region, so stronger geomagnetic activity is usually needed.
Data sources
- · NOAA SWPC Kp forecast
- · NOAA OVATION aurora model
- · Open-Meteo cloud forecast
Aurora Forecast AI Tracker
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Best Months to See the Northern Lights in Portrush
The aurora season in Portrush usually runs from September to April.
Drive away from city lights and look toward the northern horizon. Aurora visibility usually requires stronger geomagnetic activity around Kp 5.5 or higher.