Auvergne-Rhône-Alpes

Northern lights in Saint-Étienne tonight

Real-time aurora forecast for Saint-Étienne (Auvergne-Rhône-Alpes) - latitude 45.44° N, estimated Kp threshold 8.

Kp index

4.3

unsettled

Hemispheric power

North21GW

South22GW

Source: app.pulsar-si.com

Tonight in Saint-Étienne

Very unlikely

Based on Kp 4.3 and Saint-Étienne's latitude.

Seeing the northern lights from Saint-Étienne

Saint-Étienne, at 45.4° N in the Massif Central, is flanked by the Pilat to the south and the Forez mountains to the west. Auroras here are rare (Kp 7.5+ needed), but the immediate proximity of dark massifs offsets the urban pollution. The Pilat is one of the closest "dark skies" in southern France, just 25 km from the centre.

Observation conditions in Saint-Étienne

Bortle 8 in the centre. The Pilat regional park (Bortle 4, 25 km south) and the Crêt de la Perdrix (1432 m, Bortle 4) are remarkable. The Forez mountains (Bortle 5, 60 km west) and the Aubrac, further out, offer altitude skies. Avoid the Saint-Étienne basin and the Lyon axis, saturated with light pollution.

Recent auroras from Saint-Étienne

10-11 May 2024 (Kp 9): aurora from the Crêt de l'Œillon and the Pilat, red skies photographed. 24 March 2024 (Kp 8): sightings from the Forez. 5 November 2023 (Kp 7): faint aurora visible from the Crêt de la Perdrix.

What Saint-Étienne asks of the sky

Geomagnetic latitude

46.8°

31 of 40

Kp index required

Kp 8

2 / 12 months

Dark nights per year

365

365 / 365

Saint-Étienne ranks 31 of the 40 cities we track, at 46.8° geomagnetic. Annecy sits 0.1° higher , Grenoble follows at 46.3°.

The threshold to clear here is Kp 8. Twelve months of archive hold 2 nights, the most recent on 19 January 2026, and 48 since 1994. Lyon and Clermont-Ferrand and Grenoble share exactly the same threshold.

Saint-Étienne keeps full astronomical night all 365 nights of the year, which every city north of the Loire loses for part of the summer.

How to read the Kp index →

Local conditions

Light pollution

Bortle 7 of 9

SQM 18.80 mag/arcsec²

Nearest darker sky

Saint-Étienne

2 km · Bortle 4

Kp forecast, next 3 days

Source: app.pulsar-si.com. For an aurora to be visible from Saint-Étienne, Kp must exceed 8.

Wed 19 Aug

1.1

Expected max Kp

Thu 20 Aug

1.5

Expected max Kp

Fri 21 Aug

1.7

Expected max Kp

Frequently asked questions

Can you see the northern lights from Saint-Étienne?

Yes, but rarely. Typically a Kp index of ≥ 8 is needed for the aurora to become visible from Saint-Étienne (latitude 45.4° N). Major geomagnetic storms (Kp 8-9) that reach this latitude happen only a handful of times per 11-year solar cycle.

What Kp index is needed to see auroras from Saint-Étienne?

The approximate Kp threshold for Saint-Étienne is 8. Below that, auroras stay confined to high latitudes (Norway, Scotland). Above it, they gradually extend southward. A Kp of 9 gives a fair chance, 10 a strong one.

When is the best time to watch from Saint-Étienne?

Auroras are a nighttime phenomenon, best observed between roughly 10 PM and 2 AM local time, when the geomagnetic pole is tilted towards the Earth's night side. In practice, peaks depend on when a coronal mass ejection arrives - activity can spike at any hour.

Where around Saint-Étienne offers better conditions?

Move at least 40-60 km north of Saint-Étienne to escape urban light pollution and gain 1-2 magnitudes of limiting magnitude.

Nearby cities

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