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 Pennsylvania
Tonight the forecast peak is Kp 3.0. From northern Pennsylvania: not expected. From Philadelphia: not expected.
The next three nights
| Night (9 pm to 3 am) | Peak Kp | Northern Pennsylvania | Philadelphia |
|---|---|---|---|
| Wed, Nov 4 | 3.0 | Not expected | Not expected |
| Thu, Nov 5 | 2.3 | Not expected | Not expected |
| Fri, Nov 6 | 5.0 | Not expected | Not expected |
What Pennsylvania needs
The aurora reaches the northern edge of Pennsylvania at about Kp 7.6, and Philadelphia at about Kp 8.9. 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 Pennsylvania
From the cities that need the least Kp to the most:
- Erie: about Kp 7.5
- Scranton: about Kp 8.2
- Pittsburgh: about Kp 8.3
- Bethlehem: about Kp 8.6
- Allentown: about Kp 8.6
- Harrisburg: about Kp 8.6
- Reading: about Kp 8.7
- Lancaster: about Kp 8.8
- Philadelphia: about Kp 8.9
Forecast: NOAA Space Weather Prediction Center 3-day Kp forecast, refreshed every few hours. The visibility rule is approximate.