Can you see the Milky Way from San Francisco?

Not from San Francisco itself — at about Bortle 8 the dome is too bright. The darkest edge of the same metro is Tamalpais-Homestead Valley, about 10 mi out at roughly Bortle 4.

How dark is the sky across the San Francisco metro?

It varies by how close you are to the core. San Francisco itself reads about Bortle 8; the 38 towns in this light dome range down to Tamalpais-Homestead Valley at roughly Bortle 4, about 10 mi from the core. The table above sorts every town in the metro by measured darkness.

Where's the nearest certified dark-sky destination to San Francisco?

None of the 92 certified International Dark Sky Places sit within about 250 miles of San Francisco — the nearest genuinely darker option is Tamalpais-Homestead Valley within the metro itself.

San Francisco, CA — light pollution & stargazing across the metro

California · Very poor — city glow · 38 towns · 2,804,083 people in this light dome

The San Francisco, CA light dome covers 38 towns and about 2,804,083 people rated together, reading roughly Bortle 8 — a city sky (very poor — city glow) — at San Francisco itself, measured from VIIRS 2024 satellite night-lights. The darkest edge of this same dome is Tamalpais-Homestead Valley, about 10 mi out, at roughly Bortle 4. Tonight's Moon phase, cloud cover, and aurora odds load live below, computed in your browser.

1–2 3 4 5 6 7 8 9

← darker sky You: Bortle 8 · City sky brighter →

Stargazing at the San Francisco core tonight

Light-pollution reading — dome core San Francisco, CA · VIIRS 2024

Estimated Bortle class (core): 8 of 9
VIIRS radiance (core): 81 nW/cm²/sr
Naked-eye limiting mag. (core): 4.1–4.5
Darkest edge of this dome: Tamalpais-Homestead Valley · B4 · 10 mi

What you can see from the San Francisco core

The sky is bright enough to read by. Only the Moon, the planets, and the few brightest stars and clusters are visible — the constellations lose most of their fainter stars.

At an estimated Bortle 8, the faintest stars visible from San Francisco itself on a clear, moonless night run to about magnitude 4.1–4.5, and the Milky Way is not visible. Tamalpais-Homestead Valley is a short hop away (10 mi) and improves to roughly Bortle 4.

Of the 38 towns rated in this dome, most read Bortle 6 (13 towns) — spread across 5 darkness classes overall. Beyond San Francisco itself, Oakland, Concord, Vallejo round out the largest towns sharing this same light dome.

The sky from 37.8°N

Declination above +52.2° never sets here, and below −52.2° never rises — no matter how clear the night or how long you wait.

Never sets: Polaris, the Big Dipper
Never rises: Canopus, Alpha Centauri, the Southern Cross
Milky Way core: culminates 23.2° above the southern horizon — it climbs to a workable height in the south on summer nights.
Longest night: 14 h 37 m at the December solstice, 9 h 23 m in June.
Midsummer: the Sun reaches only 28.8° below the horizon at solar midnight in June — past the 18° astronomical-night mark.

Geometric, from 37.775°N, 122.419°W. How these are computed.

Every town in this light dome, darkest first

All 38 towns inside San Francisco's ~35-mile dome, each with its own measured reading.

San Francisco metro towns, darkest sky first.
Town	State	Bortle	Sky	Radiance
Tamalpais-Homestead Valley	CA	4	Rural / suburban transition	2.0
Pacifica	CA	5	Suburban sky	4.7
Larkspur	CA	5	Suburban sky	6.1
San Anselmo	CA	5	Suburban sky	7.6
Lafayette	CA	5	Suburban sky	7.7
Mill Valley	CA	6	Bright suburban sky	8.3
Clayton	CA	6	Bright suburban sky	9.7
American Canyon	CA	6	Bright suburban sky	10
Alamo	CA	6	Bright suburban sky	10
Hercules	CA	6	Bright suburban sky	11
Benicia	CA	6	Bright suburban sky	11
Orinda	CA	6	Bright suburban sky	11
Moraga	CA	6	Bright suburban sky	11
El Sobrante	CA	6	Bright suburban sky	13
Piedmont	CA	6	Bright suburban sky	14
Alameda	CA	6	Bright suburban sky	14
Petaluma	CA	6	Bright suburban sky	15
Pinole	CA	6	Bright suburban sky	17
Bay Point	CA	7	Suburban / urban transition	21
Daly City	CA	7	Suburban / urban transition	23
Bayview-Hunters Point	CA	7	Suburban / urban transition	23
Novato	CA	7	Suburban / urban transition	23
El Cerrito	CA	7	Suburban / urban transition	23
Martinez	CA	7	Suburban / urban transition	24
Albany	CA	7	Suburban / urban transition	30
San Pablo	CA	7	Suburban / urban transition	32
San Rafael	CA	7	Suburban / urban transition	33
Vallejo	CA	7	Suburban / urban transition	33
Pittsburg	CA	7	Suburban / urban transition	35
Pleasant Hill	CA	8	City sky	40
Berkeley	CA	8	City sky	41
Richmond	CA	8	City sky	45
Concord	CA	8	City sky	52
Walnut Creek	CA	8	City sky	63
Emeryville	CA	8	City sky	68
San Francisco	CA	8	City sky	81
South San Francisco	CA	8	City sky	82
Oakland	CA	8	City sky	92

Certified dark-sky destinations near San Francisco

None of the 92 certified International Dark Sky Places sit within about 250 miles of San Francisco. The darkest option inside this same metro is Tamalpais-Homestead Valley, about 10 mi out.

Other light domes near San Francisco

San Jose, CA (42 mi, core Bortle 8) , Sacramento, CA (75 mi, core Bortle 9) , and Los Angeles, CA (345 mi, core Bortle 9) are the closest other metro-scale domes tracked here — each with its own core reading and its own darkest edge.

Frequently asked questions

Can you see the Milky Way from San Francisco?: Not from San Francisco itself — at about Bortle 8 the dome is too bright. The darkest edge of the same metro is Tamalpais-Homestead Valley, about 10 mi out at roughly Bortle 4.
How dark is the sky across the San Francisco metro?: It varies by how close you are to the core. San Francisco itself reads about Bortle 8; the 38 towns in this light dome range down to Tamalpais-Homestead Valley at roughly Bortle 4, about 10 mi from the core. The table above sorts every town in the metro by measured darkness.
Where's the nearest certified dark-sky destination to San Francisco?: None of the 92 certified International Dark Sky Places sit within about 250 miles of San Francisco — the nearest genuinely darker option is Tamalpais-Homestead Valley within the metro itself.

How to read this rating

A satellite proxy, not a survey-grade reading. Sources and limits.

More in California

All California towns · Bortle scale · Tonight's Moon · Dark-sky map