Northern Lights West Valley City – Visible Tonight? Kp 7.3 Needed
From Kp 7.3 the aurora can be seen on the horizon in West Valley City, from Kp 9 high in the sky. NOAA's live 3-day Kp forecast and tonight's dark hours.
Aurora over West Valley City
- West Valley City lies at 47° geomagnetic latitude. From Kp 7.3 an aurora can show low over the northern horizon, from Kp 9 it can reach overhead – on a dark, clear night away from city lights.
Dark hours in West Valley City – the next 7 nights
- Mon, October 5: fully dark from 20:33 to 05:58, moon 26 % lit
- Tue, October 6: fully dark from 20:32 to 05:59, moon 17 % lit
- Wed, October 7: fully dark from 20:30 to 06:01, moon 10 % lit
- Thu, October 8: fully dark from 20:29 to 06:02, moon 4 % lit
- Fri, October 9: fully dark from 20:27 to 06:03, moon 1 % lit
- Sat, October 10: fully dark from 20:25 to 06:04, moon 0 % lit
- Sun, October 11: fully dark from 20:24 to 06:05, moon 1 % 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 West Valley City
- 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 11 min · 19:02–06:12
- February: 10 h 14 min · 19:34–05:48
- March: 9 h 0 min · 21:06–06:06
- April: 7 h 23 min · 21:46–05:09
- May: 5 h 45 min · 22:31–04:16
- June: 4 h 43 min · 23:07–03:50
- July: 5 h 15 min · 22:56–04:11
- August: 6 h 48 min · 22:08–04:56
- September: 8 h 27 min · 21:09–05:36
- October: 9 h 51 min · 20:18–06:09
- November: 10 h 56 min · 18:44–05:41
- December: 11 h 27 min · 18:40–06:06
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.