Northern Lights tonight in Aspen Hill, MD

Tonight in Aspen Hill

Aspen Hill sits at a geomagnetic latitude of 48.2° N, so the aurora usually needs a Kp index of about 8 or higher before it rises above the northern horizon. Tonight's NOAA forecast peaks at Kp 3 (quiet) during the dark hours, 5.0 short of what Aspen Hill needs.

The Moon is 100% illuminated (full moon), bright enough to wash out a faint aurora, so only a stronger display will stand out. For the best view look north, low on the horizon, from somewhere away from street lights.

Right now NOAA's OVATION model gives up to 0% chance of aurora in the part of the sky visible from Aspen Hill. OVATION is a short-range nowcast (30 to 90 minutes ahead), useful for deciding whether to step outside now.

3-day Kp forecast

None of the next 3 days reaches the Kp 8 that Aspen Hill needs. Kp is a global 0–9 index of geomagnetic activity, issued in 3-hour blocks (UTC); NOAA forecasts beyond 24 hours are uncertain, because storms are triggered by solar eruptions that take 1–3 days to arrive.

Why Aspen Hill needs Kp 8

The aurora forms in an oval around the geomagnetic pole, which sits in the Canadian Arctic (about 80.8° N, 72.8° W), not at the geographic pole. That is why North American cities see aurora further south than European cities at the same latitude. At Kp 0 the oval's edge is near 66° geomagnetic; each step of Kp pushes it roughly 2° toward the equator.

At 48.2° geomagnetic, Aspen Hill needs about Kp 8 for aurora low on the horizon, Kp 9 or more for a display high in the sky.

Aurora forecast for nearby cities

• Northern lights Wheaton, MD
• Northern lights North Bethesda
• Northern lights Rockville
• Northern lights Olney
• Northern lights Silver Spring
• Northern lights Bethesda
• Northern lights Gaithersburg
• Northern lights Potomac

More sky and weather

• Aurora forecast (all cities)
• Northern Taurids meteor shower
• Meteor showers
• Weather warnings