Aurora over San Francisco — tonight's forecast
Live geomagnetic conditions vs what San Francisco, USA actually needs to see the aurora borealis (northern lights).
🔵 Not visible from here
This location is too far from the auroral zone for realistic sightings — but strong storms make headlines, and the pages below show where to travel.
Kp now
2
Tonight's max (forecast)
3.67
San Francisco needs
>9
Geomagnetic lat.
42.8°
Live data: NOAA SWPC planetary K-index · refreshes every 30 min · get a free storm alert
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✈ TelegramWhat it takes to see the aurora borealis (northern lights) from San Francisco
Aurora visibility is set by your geomagnetic latitude — your position relative to Earth's magnetic pole, not the geographic one. San Francisco sits at 42.8° geomagnetic. The auroral oval hovers near 66° in quiet conditions and expands toward the equator as geomagnetic storms strengthen: roughly 2° per step of the Kp index. San Francisco is effectively outside aurora range: even the strongest storms in a century rarely push displays this far. When headlines say "aurora visible unusually far south", check this page — the live numbers above will tell you if the rare exception is happening.
How to actually catch it
- Get away from city lights with a clear view of the northern horizon — light pollution is the #1 killer of borderline displays.
- Best window: 22:00–02:00 local time; best seasons: around the equinoxes, and dark winter months at high latitudes.
- Your camera sees more than your eyes: a 5-10s phone night-mode exposure reveals green/red glow invisible to the naked eye.
- Storms spike with little warning — get a free storm alert and check Aurora forecast when Kp jumps.
FAQ
Can you see the aurora from San Francisco?
Realistically no — San Francisco sits at geomagnetic latitude 42.8°, far outside the auroral zone even during extreme storms. The nearest realistic aurora viewing means traveling toward the northern auroral zone.
What Kp index does San Francisco need for aurora?
About Kp 9.1. The auroral oval sits near 66° geomagnetic latitude in quiet conditions and pushes roughly 2° toward the equator with each Kp step; San Francisco's geomagnetic latitude is 42.8°. You don't need the oval directly overhead — NOAA notes the aurora can be seen on the horizon from up to 1000 km away, so this figure allows a conservative 5° (2.5 Kp) of that viewing distance.
When is the best time to see the aurora?
Around local midnight (22:00–02:00), on dark clear nights away from city lights, and statistically around the equinoxes (March/April and September/October). Solar maximum — happening now — delivers the most storms.
Aurora forecasts for cities near San Francisco
- Aurora forecast for Oakland — needs Kp 9.1
- Aurora forecast for San Jose — needs Kp 9.3
- Aurora forecast for Sacramento — needs Kp 8.6
- Aurora forecast for Fresno — needs Kp 9.4
- Aurora forecast for Reno — needs Kp 8
- Aurora forecast for Bakersfield — needs Kp 10
This city elsewhere on Cosmik
More from the sky over San Francisco
The aurora isn't the only show: the ISS passes over San Francisco on a predictable schedule, the Sun's live flare level tells you when the next storm is brewing, and Cosmik's live 3D map shows everything in orbit right now.
