An alert when the aurora can reach your own sky, the hours it is dark enough, and a camera that stacks a sharp shot.
AuroraCue: Aurora ForecastAn alert when the aurora can reach your own sky, the hours it is dark enough, and a camera that stacks a sharp shot.
Northern lights tonight in Colorado
Tonight the forecast peak is Kp 3.7. From northern Colorado: not expected. From Denver: not expected (too far south for all but extreme storms).
The next three nights
| Night (9 pm to 3 am) | Peak Kp | Northern Colorado | Denver |
|---|---|---|---|
| Wed, Nov 4 | 3.7 | Not expected | Not expected (too far south for all but extreme storms) |
| Thu, Nov 5 | 2.3 | Not expected | Not expected (too far south for all but extreme storms) |
| Fri, Nov 6 | n/a | No forecast yet | No forecast yet |
What Colorado needs
The aurora reaches the northern edge of Colorado at about Kp 8.4, and Denver at more than Kp 9. Kp is NOAA's 0-9 index of geomagnetic activity; the higher it goes, the farther south the aurora can be seen.
How to see it
- Get away from city lights and face north, with a clear view of the horizon.
- The best hours are usually 10 pm to 2 am, and clouds hide everything, so check the sky too.
- A phone camera on a long exposure often shows color the eye misses.
Northern lights tonight by city in Colorado
From the cities that need the least Kp to the most:
- Fort Collins: about Kp 8.6
- Greeley: about Kp 8.7
- Loveland: about Kp 8.7
- Longmont: about Kp 8.8
- Boulder: about Kp 8.9
- Broomfield: about Kp 8.9
- Thornton: about Kp 8.9
- Commerce City: about Kp 8.9
- Westminster: about Kp 8.9
- Arvada: about Kp 9.0
- Denver: about Kp 9.0
Forecast: NOAA Space Weather Prediction Center 3-day Kp forecast, refreshed every few hours. The visibility rule is approximate.