Aurora Borealis in Caerphilly
United Kingdom · 51.57°, -3.22° · geomagnetic 53.9° · needs Kp 7
Tonight's aurora forecast for Caerphilly
2%
Peak chance of a visible display tonight, from the same model the Revon app runs. Caerphilly needs Kp 7 to see anything at all, and tonight the forecast peaks at Kp 4.9. Short of the threshold, which is what most nights look like here.
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Updated 2026-09-08 10:36 UTC
Local aurora guide for Caerphilly
The aurora borealis is visible in Caerphilly on average 2.7 nights per year. This is based on historical data and a minimum geomagnetic activity threshold of Kp 7.
Caerphilly is located at 53.9° geomagnetic latitude. This latitude is favorable for viewing auroras.
The best months for aurora viewing in Caerphilly are September, August, and November. These months offer a good balance of darkness and potential aurora activity.
During June and July, there is no full darkness in Caerphilly due to the summer solstice. This limits viewing opportunities during these months.
Caerphilly experiences Bortle 7 light pollution. This indicates a suburban sky with some light pollution.
Darker skies, rated Bortle 4, can be found 42 km west-north-west near Neath Port Talbot. Bortle 5 skies are available 20 km north near Blaenau Gwent.
Nearby hills and ridges that may offer clearer views include Mynydd Dimlaith, Mynydd y Grug, and Mynydd Merthyr.
Areas with clearer horizons near Caerphilly include Mynydd Dimlaith, a hill located 3.8 km north, and Mynydd y Grug, a hill 4.5 km north-north-east.
Further afield, Mynydd Merthyr, a ridge 19.1 km north-west, and Mynydd Llangynidr, a mountain 27.8 km north-north-west, offer expansive views.
Craig y Llyn, a cliff situated 29.9 km north-west of Caerphilly, also presents a potential vantage point.
There are 53 verified aurora sightings reported within 300 km of Caerphilly between 2015 and 2016.
The historical record includes nights with Kp values of 7.0 or higher, such as March 20, 2026, January 20, 2026, and January 19, 2026.
Other notable historical nights with high Kp values include November 12, 2025 (Kp 7.33) and November 11, 2025 (Kp 8.67).
Sources: Revon analysis of NOAA planetary Kp · Revon location dataset · Solar declination and hour-angle calculation · Falchi 2016 World Atlas of artificial night sky brightness · GeoNames (CC BY 4.0) · Aurorasaurus verified positive reports
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Forecasts for places within reach of Caerphilly.