Aurora Borealis in Lahti
Finland · 60.98°, 25.66° · geomagnetic 58.4° · needs Kp 5
Tonight's aurora forecast for Lahti
33%
Peak chance of a visible display tonight, from the same model the Revon app runs. Lahti needs Kp 5 to see anything at all, and tonight the forecast peaks at Kp 4.7. Short of the threshold, which is what most nights look like here.
Get the full 30-night forecast in Revon
Updated 2026-09-08 10:35 UTC
Local aurora guide for Lahti
Lahti is located at 58.4° geomagnetic latitude. Auroras are typically visible when the planetary Kp index reaches 5 or higher.
Over the period from 2016 to 2026, an average of 20.1 nights per year in Lahti met this threshold for aurora visibility.
The darkest months in Lahti are typically from September through March. During May, June, July, and August, there is insufficient darkness for optimal aurora viewing.
Historically, the months of September, March, and October have offered the best opportunities for aurora sightings in this region.
Lahti experiences a Bortle 6 sky, indicating moderate light pollution. Areas with darker skies, such as Bortle 4 near Asikkala (30 km north) or Bortle 5 near Lahti (18 km east), offer better viewing conditions.
The local terrain includes islands like Kahvisaari (3.1 km NNW) and Vasikkasaari (4.1 km NW), as well as hills such as Parikanmäki (3.8 km E) and Ritamäki (4.0 km NNW), and the lake Merrasjärvi (4.1 km NNE).
Geographic features near Lahti include the island of Kahvisaari, located 3.1 km north-north-west. Parikanmäki, a hill, is situated 3.8 km east of the city.
Further points of interest include Ritamäki hill, 4.0 km north-north-west, and Merrasjärvi lake, 4.1 km north-north-east. The island of Vasikkasaari is also 4.1 km north-west of Lahti.
Between 2016 and 2026, there were approximately 20.1 nights per year suitable for aurora viewing in Lahti based on Kp index.
Aurorasaurus has recorded 41 verified sightings within 300 km of Lahti between January 2015 and December 2016.
Specific qualifying nights with Kp 5.0 or higher occurred on March 20, 21, 22, 23, and 24, 2026.
Sources: Revon location dataset · 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 Lahti 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 Lahti.