Northern lights tonight in Philadelphia, Pennsylvania: unlikely
Unlikely tonight. Philadelphia needs about Kp 8.5; tonight's forecast reaches Kp 2.7, cloud cover 95 %. Dark from 7:21 PM to 6:13 AM, moon 33 % lit.
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Tonight in Philadelphia
| Local time | Cloud cover | Kp forecast | Aurora reaches the horizon? |
|---|---|---|---|
| 8:00 PM | 100 % | 1.7 | No |
| 9:00 PM | 53 % | 1.7 | No |
| 10:00 PM | 100 % | 1.7 | No |
| 11:00 PM | 100 % | 1.7 | No |
| 12:00 AM | 94 % | 1.7 | No |
| 1:00 AM | 100 % | 1.7 | No |
| 2:00 AM | 100 % | 1.3 | No |
| 3:00 AM | 100 % | 1.3 | No |
| 4:00 AM | 100 % | 1.3 | No |
| 5:00 AM | 100 % | 1.3 | No |
| 6:00 AM | 100 % | 1.3 | No |
Where to look in Philadelphia
At Philadelphia's latitude the aurora appears low on the northern horizon during geomagnetic storms (Kp 9 or more), often as a green or reddish glow rather than dancing curtains overhead. Drive away from the city lights to a place with an open view to the north – a lake shore, a field or a hilltop – and use a phone camera in night mode, which picks up color the eye misses.
A bright moon and haze both wash out a faint display; check the hourly cloud cover above and look again later in the evening, when NOAA's short-term OVATION model gives a better picture of the next hour.
Northern lights in Philadelphia
Can I see the northern lights in Philadelphia, Pennsylvania tonight?
Unlikely: unlikely tonight. Philadelphia needs about Kp 8.5; the forecast for its dark hours tonight is up to Kp 2.7, with 95 % cloud cover on average.
What Kp is needed to see the aurora in Philadelphia, Pennsylvania?
Philadelphia: about Kp 8.5 (geomagnetic latitude 49.1°).
What is the best time to see the aurora?
Usually between about 10 PM and 2 AM local time, when your part of the Earth faces the night-side of the auroral oval – but during a strong storm it can appear as soon as it is dark. Give your eyes 15–20 minutes away from screens and lights.
Why can my phone see the aurora when I can't?
A phone camera's long exposure collects far more light than the eye and sees color better in the dark. At lower latitudes a faint aurora often looks grey or white to the eye and green or pink on a 3-second phone shot – try night mode pointed north.
How accurate is the forecast?
Kp forecasts a day or more ahead come from observations of the Sun and are uncertain by a step or two; the timing of a storm's arrival can be off by many hours. The OVATION model is good for the next 30–90 minutes. Check the page again in the evening.
Nearby
Sources: NOAA Space Weather Prediction Center (planetary Kp index and 3-day forecast, OVATION aurora model, G-scale outlook), Open-Meteo hourly cloud cover; sun and moon computed by 77.today. The aurora is notoriously hard to forecast beyond an hour or two – treat this as a guide.