Aurora Borealis in Jämsä
Finland · 61.86°, 25.19° · geomagnetic 59.3° · needs Kp 5
Tonight's aurora forecast for Jämsä
46%
Peak chance of a visible display tonight, from the same model the Revon app runs. Jämsä 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 Jämsä
Jämsä is located at 59.3° geomagnetic latitude. Auroras are typically visible here when the planetary Kp index reaches 5.
On average, there are about 19.8 nights per year suitable for aurora viewing in this region. The historical record spans from April 2, 2016, to March 30, 2026.
The best months for aurora viewing in Jämsä are September, October, and March. These months offer a good balance of darkness and potential aurora activity.
During May, June, July, and August, the region experiences periods without full darkness, which can impact viewing opportunities.
The Jämsä area has a Bortle scale rating of 5, indicating a suburban sky brightness. Areas with Bortle 4 conditions can be found approximately 15 km north-northeast of Jämsä.
Other Bortle 5 areas are located about 13 km south-southeast of Jämsä. Several lakes and hills surround the area, including Suolammi, Asemenjärvi, Pellavassaari, Suolamminmäki, and Pieni Ahonvuori.
Surrounding Jämsä, natural features like Suolammi lake lie 3.1 km to the north. Asemenjärvi lake is situated 3.1 km to the east.
Pellavassaari island is located 3.3 km east-northeast of Jämsä. The hills of Suolamminmäki and Pieni Ahonvuori are found 3.3 km and 3.5 km north respectively.
There are 164 verified aurora reports within 300 km of Jämsä between January 1, 2015, and December 31, 2016.
Notable qualifying nights with Kp 5.0 or higher occurred on March 20-24, 2026, with Kp values ranging from 5.0 to 7.0.
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
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Revon watches the Jämsä forecast and pushes an alert when the odds for tonight clear your threshold — no checking, no guessing.
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Forecasts for places within reach of Jämsä.