Located in City and County of San Francisco, California, Arch Rock is a natural arch. It sits roughly 36 km (22 mi) SW of Bolinas.
Wikidata describes it as: “Arch in San Francisco”.
Sunrise & sunset directions
At Arch Rock the sunrise point swings a long way through the year: about 59° (ENE) at the June solstice and 120° (ESE) in late December. Sunset moves from 301° (WNW) in June to 241° (WSW) in December, and the midday sun climbs to 76° in summer but only 29° in winter.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 7:16 AM | 90° E | 7:24 PM | 271° W | 52° | 12h 08m |
| June solstice (Jun 21) | 5:51 AM | 59° ENE | 8:38 PM | 301° WNW | 76° | 14h 46m |
| September equinox (Sep 22) | 7:01 AM | 89° E | 7:11 PM | 271° W | 53° | 12h 10m |
| December solstice (Dec 21) | 7:24 AM | 120° ESE | 4:57 PM | 241° WSW | 29° | 9h 33m |
Azimuth is measured clockwise from true north (90° = east, 270° = west). Computed for 2026; values change by less than a degree from year to year.
Golden hour & blue hour by month
Arches glow when reflected light bounces off nearby rock — the underside of an arch often turns bright orange just after sunrise or before sunset.
| Month (15th) | Blue hour starts | Sunrise | Golden hour ends | Golden hour starts | Sunset | Blue hour ends | Daylight |
|---|---|---|---|---|---|---|---|
| January | 6:58 AM | 7:27 AM | 8:06 AM | 4:38 PM | 5:17 PM | 5:46 PM | 9h 51m |
| February | 6:36 AM | 7:03 AM | 7:39 AM | 5:15 PM | 5:52 PM | 6:18 PM | 10h 49m |
| March | 6:58 AM | 7:24 AM | 7:59 AM | 6:45 PM | 7:20 PM | 7:46 PM | 11h 56m |
| April | 6:10 AM | 6:37 AM | 7:13 AM | 7:13 PM | 7:48 PM | 8:15 PM | 13h 10m |
| May | 5:34 AM | 6:03 AM | 6:40 AM | 7:38 PM | 8:15 PM | 8:45 PM | 14h 12m |
| June | 5:19 AM | 5:51 AM | 6:30 AM | 7:57 PM | 8:36 PM | 9:07 PM | 14h 45m |
| July | 5:33 AM | 6:03 AM | 6:41 AM | 7:56 PM | 8:34 PM | 9:05 PM | 14h 31m |
| August | 6:01 AM | 6:29 AM | 7:04 AM | 7:30 PM | 8:06 PM | 8:34 PM | 13h 38m |
| September | 6:28 AM | 6:55 AM | 7:29 AM | 6:47 PM | 7:21 PM | 7:48 PM | 12h 27m |
| October | 6:55 AM | 7:21 AM | 7:56 AM | 6:00 PM | 6:36 PM | 7:02 PM | 11h 15m |
| November | 6:25 AM | 6:53 AM | 7:31 AM | 4:24 PM | 5:02 PM | 5:30 PM | 10h 09m |
| December | 6:52 AM | 7:21 AM | 8:02 AM | 4:14 PM | 4:55 PM | 5:25 PM | 9h 34m |
Local time (America/Los Angeles), including daylight saving time. Golden hour runs from about −4° to +6° solar altitude, so the morning golden hour begins during blue hour, before sunrise.
Milky Way & night sky
From Arch Rock, the Milky Way core is visible in a dark sky from March through September. June gives the longest window (about 5.3 hours on a moonless night), and the core peaks around 23° above the southern horizon. Our light-pollution model puts the sky at about Bortle 4 (rural / suburban transition), good enough for detailed Milky Way images.
| Month | Core visible (15th) | Hours | Max altitude | Direction |
|---|---|---|---|---|
| January | Below 10° in darkness | — | -1° | — |
| February | 5:10 AM – 5:30 AM | 0.3 | 13° | SE → SE |
| March | 4:17 AM – 5:47 AM | 1.5 | 20° | SE → SSE |
| April | 2:21 AM – 5:01 AM | 2.7 | 23° | SE → S |
| May | 12:20 AM – 4:10 AM | 3.8 | 23° | SE → S |
| June | 10:31 PM – 3:51 AM | 5.3 | 23° | SE → SW |
| July | 10:24 PM – 2:24 AM | 4.0 | 23° | SSE → SW |
| August | 9:44 PM – 12:24 AM | 2.7 | 23° | S → SW |
| September | 8:50 PM – 10:20 PM | 1.5 | 20° | SSW → SW |
| October | 8:03 PM – 8:23 PM | 0.3 | 13° | SW → SW |
| November | Below 10° in darkness | — | 1° | — |
| December | Below 10° in darkness | — | -19° | — |
Window when the galactic core is at least 10° high during astronomical darkness on the 15th of each month. Pick nights within a few days of the new moon. Plan exact nights with the Milky Way planner.
Estimated sky darkness: 4 Bortle 4 — Rural / suburban transition. Light domes are visible in several directions; the Milky Way is clear but lacks detail near the horizon. Modeled zenith brightness ≈ 20.83 mag/arcsec².
Weather & best season
Long-term NASA satellite data for this area show June as the clearest month (about 53% average cloud cover) and August as the cloudiest (71%). September is the warmest month and April the coldest, which matters for gear, snow access and how long batteries last at night.
Average cloud cover (%)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| High °F | 63 | 60 | 60 | 65 | 65 | 65 | 64 | 65 | 67 | 67 | 63 | 63 |
| Low °F | 44 | 45 | 45 | 47 | 48 | 50 | 52 | 53 | 53 | 52 | 49 | 46 |
| Precip. (in) | 3.2 | 3.4 | 2.6 | 1.3 | 0.7 | 0.4 | 0.1 | 0.1 | 0.2 | 1.0 | 2.3 | 4.1 |
Monthly climatology for the surrounding 1° grid cell from NASA POWER (MERRA-2). Mountain sites can be colder and cloudier than the cell average.
Photography tips for this natural arch
- At night, arches make classic Milky Way foregrounds; low-level lighting or blue hour exposures keep the rock detailed.
- Use a wide lens and get close to emphasize the span against the sky.
- Never climb on arches; many are fragile and climbing is prohibited on park lands.
- Midday sun creates hard shadows, but can light the underside through reflection in narrow canyons.
- Tell someone where you're going in remote areas and carry the ten essentials.
Season: Spring and autumn offer mild temperatures in desert arch country; summer heat is extreme at midday.
Suggested gear: Ultra-wide lens, Tripod, Headlamp, Plenty of water. Work out exposures with the depth of field, ND filter and NPF rule calculators.
Nearby photo spots
Other locations within 25 km of Arch Rock, closest first.
Lighthouse
National Wildlife Refuge
Natural ArchFAQ
When is the best time to photograph Arch Rock?
What time is golden hour at Arch Rock?
Where does the sun rise and set at Arch Rock?
Can you see the Milky Way from Arch Rock?
Do you need a permit to photograph at Arch Rock?
How far is Arch Rock from Bolinas?
Sources
Location data: Wikidata, USGS GNIS / GeoNames. Sun, moon and Milky Way times are computed by LWPhoto Atlas for 2026. Climate: NASA POWER. Sky darkness is a population-based estimate (Walker's law), not a measurement. See data sources & licenses.