Aurora Borealis in Cornwall
Canada · 45.02°, -74.73° · geomagnetic 54.4° · needs Kp 7
Tonight in Cornwall
1%
Peak chance of a visible display tonight, from the same model the Revon app runs. Cornwall needs Kp 7 to see anything at all, and tonight the forecast peaks at Kp 5.1. Short of the threshold, which is what most nights look like here.
Updated 2026-08-02 20:20 UTC
The next 30 nights in Cornwall
Every night to come, scored the same way as tonight. The best of the open week is Sunday 2 Aug at 1%. Not one of the seven reaches the Kp 7 that Cornwall needs, which is normal rather than unlucky — it averages 3.2 viable nights a year. 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 Cornwall
Revon aurora model over the NOAA Kp forecast and 27-day outlook
How often the aurora borealis reaches Cornwall
3.2 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
Wait for an alert; do not book a week
At Kp 7, Cornwall needs a severe geomagnetic storm before anything shows above the northern horizon. Storms that size arrive a handful of times per solar cycle and announce themselves a day or two ahead. Watching for one beats picking dates and hoping.
Hours of true darkness, month by month
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 11.4 | 10.3 | 8.9 | 7.0 | 4.9 | 3.3 | 4.1 | 6.2 | 8.2 | 9.9 | 11.1 | 11.7 |
Solar declination and hour angle at −18°
Getting clear of the light
The sky over Cornwall reads Bortle 5. Getting clear of the built-up area makes a visible difference on a marginal night.
- 3 km south-west → Bortle 5
- 81 km north — around Grenville-sur-la-Rouge → 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, May, September and August came out ahead in Cornwall. 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 Cornwall viewing season.
- 13 Aug 2026
- 11 Sep 2026
- 11 Oct 2026
- 09 Nov 2026
- 09 Dec 2026
- 07 Jan 2027
- 06 Feb 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 Nuuk, 2,564 km north-north-east in Greenland.
| Cornwall | Nuuk | |
|---|---|---|
| Kp needed | 7 | 3 |
| Nights per year | 3.2 | 171.4 |
| Geomagnetic latitude | 54.4° | 72.6° |
Confirmed reports from this area
53 verified sightings were logged within 300 km of Cornwall 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 Cornwall
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 Cornwall.
- Farlingers Point — headland5.2 km east-north-east
- Pilon Island — island5.2 km east-north-east
- First Crab — island5.4 km east
- Flanigans Point — headland7.7 km east-north-east
- Lairds Hill — hill14.9 km north
- Sandy Hill — hill14.9 km north
Places from GeoNames (CC BY 4.0)
Where to stay
Anywhere on the outskirts of Cornwall will do; what matters is being able to step outside and check the sky without a drive first.
- Ramada Inn Cornwall 1.6 km from the centre
- Ramada Hotel And Conference Ce 1.7 km from the centre
- Econo Lodge Cornwall 2.0 km from the centre
- Howard Johnson Cornwall 2.0 km from the centre
- Days Inn Cornwall Ot 2.5 km from the centre
- Best Western Parkway Inn 2.7 km from the centre
Places from GeoNames (CC BY 4.0) — confirm before booking
The last nights it was visible here
Nights in the last decade when the storm was strong enough for Cornwall and the sky was dark enough to show it.
| Date | Peak |
|---|---|
| 2026-03-20 | Kp 7.0 |
| 2026-01-20 | Kp 7.67 |
| 2026-01-19 | Kp 8.67 |
| 2025-11-12 | Kp 7.33 |
| 2025-11-11 | Kp 8.67 |
NOAA planetary Kp
Know when it is worth going outside
Revon watches the Cornwall forecast and pushes an alert when the odds for tonight clear your threshold — no checking, no guessing.
Common questions about the aurora borealis in Cornwall
Can you see the aurora borealis from Cornwall?
Yes. On the last 10.0 years of NOAA Kp records, Cornwall had about 3.2 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 Cornwall?
Kp 7. Cornwall sits at geomagnetic latitude 54.4°, and the auroral oval only reaches that far from the pole once activity hits Kp 7. Storms that size occur about 3.2 nights a year.
When is the best time of year to see the aurora borealis in Cornwall?
May, September and August. Those months scored highest once both conditions are counted together: geomagnetic activity and enough hours of real darkness.
Where can you escape the light pollution near Cornwall?
The centre of Cornwall reads Bortle 5. The nearest sky at Bortle 4 is about 81 km north around Grenville-sur-la-Rouge. On a marginal night that drive matters more than the forecast does.
Where is the nearest place to Cornwall with reliable aurora borealis?
Nuuk, Greenland — 2,564 km north-north-east. It needs only Kp 3 and averages 171.4 viable nights a year against 3.2 in Cornwall.
Nearby towns
Forecasts for places within reach of Cornwall.