Northern Lights Thunder Bay – Visible Tonight? Kp 2.7 Needed

From Kp 2.7 the aurora can be seen on the horizon in Thunder Bay, from Kp 4.7 high in the sky. NOAA's live 3-day Kp forecast and tonight's dark hours.

Aurora over Thunder Bay

  • Thunder Bay lies at 57° geomagnetic latitude. From Kp 2.7 an aurora can show low over the northern horizon, from Kp 4.7 it can reach overhead – on a dark, clear night away from city lights.

Dark hours in Thunder Bay – the next 7 nights

  • Thu, October 8: fully dark from 21:05 to 06:24, moon 5 % lit
  • Fri, October 9: fully dark from 21:03 to 06:25, moon 1 % lit
  • Sat, October 10: fully dark from 21:01 to 06:27, moon 0 % lit
  • Sun, October 11: fully dark from 20:59 to 06:28, moon 1 % lit
  • Mon, October 12: fully dark from 20:57 to 06:29, moon 4 % lit
  • Tue, October 13: fully dark from 20:55 to 06:31, moon 9 % lit
  • Wed, October 14: fully dark from 20:53 to 06:32, moon 16 % lit

Which Kp is enough where?

  • Reykjavik: On the horizon from Kp 0 · High in the sky from Kp 0
  • Tromsø: On the horizon from Kp 0 · High in the sky from Kp 0
  • Edinburgh: On the horizon from Kp 2 · High in the sky from Kp 4
  • Oslo: On the horizon from Kp 1.3 · High in the sky from Kp 3.3
  • Stockholm: On the horizon from Kp 2.3 · High in the sky from Kp 4
  • Helsinki: On the horizon from Kp 2.3 · High in the sky from Kp 4.3
  • Copenhagen: On the horizon from Kp 3.3 · High in the sky from Kp 5.3
  • Hamburg: On the horizon from Kp 4.3 · High in the sky from Kp 6.3
  • Berlin: On the horizon from Kp 5 · High in the sky from Kp 7
  • London: On the horizon from Kp 4.3 · High in the sky from Kp 6.3
  • Warsaw: On the horizon from Kp 5.7 · High in the sky from Kp 7.7
  • Munich: On the horizon from Kp 7 · High in the sky from Kp 9
  • Paris: On the horizon from Kp 6 · High in the sky from Kp 8
  • Toronto: On the horizon from Kp 4.7 · High in the sky from Kp 6.7
  • Data: NOAA Space Weather Prediction Center

How long it gets fully dark in Thunder Bay

  • The night after the 15th of each month: how long the sun stays more than 18° below the horizon. An aurora needs that dark sky – far north, summer has none at all.
  • January: 11 h 29 min · 19:21–06:51
  • February: 10 h 13 min · 20:04–06:17
  • March: 8 h 35 min · 21:47–06:22
  • April: 6 h 21 min · 22:46–05:06
  • May: 3 h 45 min · 00:00–03:45
  • June: 0 h 56 min · 01:29–02:25
  • July: 2 h 40 min · 00:43–03:23
  • August: 5 h 29 min · 23:17–04:45
  • September: 7 h 51 min · 21:56–05:47
  • October: 9 h 43 min · 20:51–06:34
  • November: 11 h 10 min · 19:07–06:16
  • December: 11 h 50 min · 18:57–06:47

How to see it

  • Look toward the pole: North in the northern hemisphere, south in the southern – away from city lights.
  • Use your phone's night mode: A camera shows colours the eye cannot see yet – the aurora often looks grey at first.
  • Be patient: The aurora comes in bursts, often 20–30 minutes apart.
  • Check the clouds: Without a clear view to the horizon nothing helps.

FAQ

  • What does the Kp index mean? The Kp index measures from 0 to 9 how disturbed Earth's magnetic field is. The higher it is, the farther the auroral oval moves toward the equator. From Kp 5 NOAA speaks of a geomagnetic storm.
  • When is the best time for the northern lights? Around magnetic midnight – in central Europe roughly between 10 pm and 2 am – and around the equinoxes in spring and autumn, when storms are a little more frequent.
  • How reliable is the forecast? The Kp forecast for the next hours is quite good, for two or three days only rough: solar storms take one to three days to reach Earth, and their exact strength often only shows shortly before.