Aurora Borealis in Carmarthen
United Kingdom · 51.86°, -4.31° · geomagnetic 54.4° · needs Kp 7
Tonight's aurora forecast for Carmarthen
2%
Peak chance of a visible display tonight, from the same model the Revon app runs. Carmarthen 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.
Get the full 30-night forecast in Revon
Updated 2026-09-08 10:36 UTC
Local aurora guide for Carmarthen
Carmarthen is at a geomagnetic latitude of 54.4°.
Auroras are typically visible here when the Kp index reaches 7.
On average, there are about 2.7 nights per year when conditions are suitable for viewing.
The best months for aurora viewing in Carmarthen are September, August, and November.
June and July experience too much daylight for full darkness.
Carmarthen has a Bortle scale rating of 5.
Areas with Bortle 4 ratings are found 17 km north-east near Carmarthenshire.
Areas with Bortle 5 ratings are found 12 km south-east near Carmarthenshire.
Foelcwan, a hill, is located 3.1 km north-west of Carmarthen.
Pentre'r'hydd, a hill, is located 3.1 km west of Carmarthen.
Mynydd Figyn, a mountain, is located 21.2 km east-north-east of Carmarthen.
There have been 72 verified aurora sightings reported within 300 km of Carmarthen between 2015 and 2016.
The period from 2016 to 2026 has recorded several nights with high Kp values, including March 20, 2026 (Kp 7.0), January 20, 2026 (Kp 7.67), and January 19, 2026 (Kp 8.67).
Sources: Revon analysis of NOAA planetary Kp · Solar declination and hour-angle calculation · Falchi 2016 World Atlas of artificial night sky brightness · GeoNames (CC BY 4.0) · Aurorasaurus verified positive reports
Know when it is worth going outside
Revon watches the Carmarthen forecast and pushes an alert when the odds for tonight clear your threshold — no checking, no guessing.
Nearby towns
Forecasts for places within reach of Carmarthen.