Northern Lights tonight in Donostia / San Sebastián

Tonight in Donostia / San Sebastián

Donostia / San Sebastián sits at a geomagnetic latitude of 45.7° N, so the aurora usually needs a Kp index of about 9 or higher before it rises above the northern horizon. Tonight's NOAA forecast peaks at Kp 1.7 (quiet) during the dark hours, 7.3 short of what Donostia / San Sebastián needs.

Open-Meteo expects about 0% cloud cover on average between 8 pm and 7 am local time, with 11 of 11 dark hours mostly clear (30% cloud or less).

The Moon is 99% illuminated (full moon), bright enough to wash out a faint aurora, so only a stronger display will stand out. For the best view look north, low on the horizon, from somewhere away from street lights.

Right now NOAA's OVATION model gives up to 0% chance of aurora in the part of the sky visible from Donostia / San Sebastián. OVATION is a short-range nowcast (30 to 90 minutes ahead), useful for deciding whether to step outside now.

3-day Kp forecast

None of the next 3 days reaches the Kp 9 that Donostia / San Sebastián needs. Kp is a global 0–9 index of geomagnetic activity, issued in 3-hour blocks (UTC); NOAA forecasts beyond 24 hours are uncertain, because storms are triggered by solar eruptions that take 1–3 days to arrive.

Why Donostia / San Sebastián needs Kp 9

The aurora forms in an oval around the geomagnetic pole, which sits in the Canadian Arctic (about 80.8° N, 72.8° W), not at the geographic pole. That is why the Kp a city needs depends on its geomagnetic rather than its geographic latitude. At Kp 0 the oval's edge is near 66° geomagnetic; each step of Kp pushes it roughly 2° toward the equator.

At 45.7° geomagnetic, Donostia / San Sebastián needs about Kp 9 for aurora low on the horizon, Kp 9 or more for a display high in the sky.

Aurora forecast for nearby cities

• Northern lights Pamplona
• Northern lights Gasteiz / Vitoria
• Northern lights Bilbao
• Northern lights Barakaldo
• Northern lights Santander
• Northern lights Bordeaux
• Northern lights Bergerac
• Northern lights Toulouse

More sky and weather

• Aurora forecast (all cities)
• Northern Taurids meteor shower
• Meteor showers
• Weather warnings