Northern Lights tonight in Worcester, MA

Tonight in Worcester

Worcester sits at a geomagnetic latitude of 51.5° N, so the aurora usually needs a Kp index of about 6 or higher before it rises above the northern horizon. Tonight's NOAA forecast peaks at Kp 3 (quiet) during the dark hours, 3.0 short of what Worcester needs.

Open-Meteo expects about 1% cloud cover on average between 7 pm and 7 am local time, with 12 of 12 dark hours mostly clear (30% cloud or less).

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 Worcester. 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 6 that Worcester 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 Worcester needs Kp 6

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 51.5° geomagnetic, Worcester needs about Kp 6 for aurora low on the horizon, Kp 8 or more for a display high in the sky.

Aurora forecast for nearby cities

• Northern lights Shrewsbury, MA
• Northern lights Marlborough
• Northern lights Milford, MA
• Northern lights Leominster
• Northern lights Framingham Center
• Northern lights Framingham
• Northern lights Fitchburg
• Northern lights Woonsocket

More sky and weather

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