Northern Lights tonight in Lahti

Tonight in Lahti

Lahti sits at a geomagnetic latitude of 58.4° N, so the aurora usually needs a Kp index of about 3 or higher before it rises above the northern horizon. Tonight's NOAA forecast peaks at Kp 3 (quiet) during the dark hours, which is enough for Lahti.

The Moon is 100% 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 15% chance of aurora in the part of the sky visible from Lahti. OVATION is a short-range nowcast (30 to 90 minutes ahead), useful for deciding whether to step outside now.

3-day Kp forecast

1 of the next 3 days reach the Kp 3 that Lahti 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 Lahti needs Kp 3

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 58.4° geomagnetic, Lahti needs about Kp 3 for aurora low on the horizon, Kp 5 or more for a display high in the sky. Jyväskylä, 140 km away, needs about Kp 2.

Aurora forecast for nearby cities

• Northern lights Vantaa
• Northern lights Helsinki
• Northern lights Espoo
• Northern lights Tampere
• Northern lights Jyväskylä
• Northern lights Tallinn
• Northern lights Turku
• Northern lights Kuopio

More sky and weather

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