Aurora Borealis in Grimstad

Norway · 58.34°, 8.59° · geomagnetic 58.5° · needs Kp 5

Tonight's aurora forecast for Grimstad

49%

Peak chance of a visible display tonight, from the same model the Revon app runs. Grimstad needs Kp 5 to see anything at all, and tonight the forecast peaks at Kp 4.8. Short of the threshold, which is what most nights look like here.

Tonight Tue 08 Sep
49%
18
20
22
00
02
04
06

Get the full 30-night forecast in Revon

Updated 2026-09-08 10:35 UTC

Local aurora guide for Grimstad

Grimstad is at a geomagnetic latitude of 58.5 degrees. Auroras are typically visible at this latitude when the Kp index reaches 5.

On average, there are 21.7 nights per year when conditions are suitable for aurora viewing in Grimstad. The historical record spans from 2016 to 2026.

The best months for aurora viewing in Grimstad are September, March, and October. These months offer a good balance of darkness and aurora activity.

During May, June, July, and August, there is not enough full darkness for optimal aurora viewing.

Grimstad experiences Bortle 7 light pollution. Areas with Bortle 4 skies, offering darker conditions, can be found 14 km south-east of the town.

Notable elevated terrain near Grimstad includes Trollerhei (3.0 km north), Brenneåsen (3.0 km north-north-west), and Bratteberg (3.1 km west-north-west). Coastal features include Kalvøyhaue (3.4 km east) and Håneset (3.5 km east).

In the vicinity of Grimstad, Trollerhei is a hill located 3.0 km to the north. Brenneåsen, another hill, is situated 3.0 km north-north-west.

To the west-north-west, 3.1 km away, is Bratteberg, characterized by cliffs. Along the coast to the east, Kalvøyhaue is a headland 3.4 km from Grimstad, with Håneset being another headland 3.5 km to the east.

There have been 25 verified aurora sightings reported within 300 km of Grimstad between January 1, 2015, and December 31, 2016.

The historical record indicates viable aurora nights occurred on March 20-24, 2026, with Kp values ranging from 5.0 to 7.0. This record spans from 2016 to 2026.

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 Grimstad forecast and pushes an alert when the odds for tonight clear your threshold — no checking, no guessing.

Get aurora alerts on iPhone

Nearby towns

Forecasts for places within reach of Grimstad.