Aurora Borealis in Mäntsälä
Finland · 60.63°, 25.32° · geomagnetic 58.1° · needs Kp 5
Tonight in Mäntsälä
38%
Peak chance of a visible display tonight, from the same model the Revon app runs. Mäntsälä needs Kp 5, and tonight the forecast peaks at Kp 5.7. That is on the threshold rather than over it, so cloud and moonlight will decide the night.
Updated 2026-08-02 20:20 UTC
The next 30 nights in Mäntsälä
Every night to come, scored the same way as tonight. The best of the open week is Sunday 2 Aug at 38%. One of the seven reaches the Kp 5 that Mäntsälä needs: Sunday 2 Aug, at Kp 5.7. The 23 nights past the seven-day window move with the 27-day solar rotation and are updated daily in the app.
Nights 8–30 unlock in the Revon app
See all 30 nights for Mäntsälä
Revon aurora model over the NOAA Kp forecast and 27-day outlook
How often the aurora borealis reaches Mäntsälä
20.4 nights a year, averaged across 10.0 years of records
| Storm level | Nights / year |
|---|---|
| Kp 4 | 83.4 |
| Kp 5 | 28.7 |
| Kp 6 | 9.3 |
| Kp 7 | 3.2 |
| Kp 8 | 1.2 |
NOAA planetary Kp, 2016-04-02 to 2026-03-30
Worth watching through the dark half of the year
Kp 5 is a moderate storm — not an everyday event, but common enough that a patient observer in Mäntsälä sees the aurora borealis most winters.
Hours of true darkness, month by month
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 12.1 | 10.2 | 7.6 | 2.7 | 0.0 | 0.0 | 0.0 | 0.0 | 6.1 | 9.4 | 11.6 | 12.6 |
Solar declination and hour angle at −18°
Nothing to see from May to August
Through those months the sun never falls more than 18° below the Mäntsälä horizon, so the sky never darkens fully. Plan around the darker half of the year.
Getting clear of the light
Mäntsälä is small enough that its own lights are a minor problem — the centre reads Bortle 6. Walking to the edge of town is often escape enough.
- 18 km south-east — around Askola → Bortle 5
- 65 km north-east — around Iitti → Bortle 4
Falchi 2016 World Atlas (DOI: 10.5880/GFZ.1.4.2016.001)
The months that actually deliver
Counting only nights that were both stormy enough and dark enough, September, March and October came out ahead in Mäntsälä. That is storm season and darkness overlapping — the equinoxes tend to be geomagnetically active, and the nights are already long by then.
Darkest nights of the coming year
A bright moon washes out a weak display as effectively as street lighting. These new moons fall inside the Mäntsälä viewing season.
- 11 Sep 2026
- 11 Oct 2026
- 09 Nov 2026
- 09 Dec 2026
- 07 Jan 2027
- 06 Feb 2027
- 08 Mar 2027
Where it is close to a certainty
If you would rather plan a trip than wait for a storm, the nearest place with genuinely frequent aurora is Rovaniemi, 653 km north in Finland.
| Mäntsälä | Rovaniemi | |
|---|---|---|
| Kp needed | 5 | 3 |
| Nights per year | 20.4 | 171.4 |
| Geomagnetic latitude | 58.1° | 63.6° |
Confirmed reports from this area
41 verified sightings were logged within 300 km of Mäntsälä between 2015-01-01 and 2016-12-31. Rare is not the same as impossible.
Aurorasaurus verified positive reports
Where the horizon opens up near Mäntsälä
The display sits low on the northern horizon, so what beats a better forecast is open ground facing that way. Height gets you above the town glow; water gives you an unbroken skyline. These are within a short drive of Mäntsälä.
- Heinilänmäki — hill3.3 km east
- Luotomäki — hill3.6 km west
- Iso-Vuotava — lake5.3 km east-north-east
- Korpilammi — lake5.5 km east-north-east
- Pukkisaari — island8.6 km north-west
- Pillikari — island8.7 km north-west
Places from GeoNames (CC BY 4.0)
What to do with the daylight
Aurora watching is a night job, and in winter that leaves a short, bright day to fill. Close to Mäntsälä you will find Haarajoki DGPS-Transmiter, and for a day when the cloud sits low, Sepänmäen Käsityömuseo and Alikartano are indoors and near by.
Keep the daylight loose: the sky decides the evening, and the forecast can turn within a few hours.
Places from GeoNames (CC BY 4.0)
The last nights it was visible here
Nights in the last decade when the storm was strong enough for Mäntsälä and the sky was dark enough to show it.
| Date | Peak |
|---|---|
| 2026-03-24 | Kp 5.0 |
| 2026-03-23 | Kp 5.0 |
| 2026-03-22 | Kp 6.67 |
| 2026-03-21 | Kp 6.0 |
| 2026-03-20 | Kp 7.0 |
NOAA planetary Kp
Know when it is worth going outside
Revon watches the Mäntsälä forecast and pushes an alert when the odds for tonight clear your threshold — no checking, no guessing.
Common questions about the aurora borealis in Mäntsälä
Can you see the aurora borealis from Mäntsälä?
Yes. On the last 10.0 years of NOAA Kp records, Mäntsälä had about 20.4 nights a year when the storm was strong enough and the sky dark enough at the same time.
What Kp index do you need to see the aurora borealis in Mäntsälä?
Kp 5. Mäntsälä sits at geomagnetic latitude 58.1°, and the auroral oval only reaches that far from the pole once activity hits Kp 5. Storms that size occur about 28.7 nights a year.
When is the best time of year to see the aurora borealis in Mäntsälä?
September, March and October. Those months scored highest once both conditions are counted together: geomagnetic activity and enough hours of real darkness. From May to August the sky over Mäntsälä never gets fully dark, so nothing is visible however strong the storm.
Where can you escape the light pollution near Mäntsälä?
The centre of Mäntsälä reads Bortle 6. The nearest sky at Bortle 4 is about 65 km north-east around Iitti. On a marginal night that drive matters more than the forecast does.
Where is the nearest place to Mäntsälä with reliable aurora borealis?
Rovaniemi, Finland — 653 km north. It needs only Kp 3 and averages 171.4 viable nights a year against 20.4 in Mäntsälä.
Nearby towns
Forecasts for places within reach of Mäntsälä.