Located in San Juan County, Washington, Cavern Falls is a waterfall at about 183 m (600 ft) above sea level. It sits roughly 18.8 km (11.7 mi) NE of Friday Harbor.
Sunrise & sunset directions
At Cavern Falls the sunrise point swings a long way through the year: about 52° (NE) at the June solstice and 126° (SE) in late December. Sunset moves from 308° (NW) in June to 234° (SW) in December, and the midday sun climbs to 65° in summer but only 18° in winter.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 7:15 AM | 89° E | 7:24 PM | 271° W | 41° | 12h 09m |
| June solstice (Jun 21) | 5:09 AM | 52° NE | 9:18 PM | 308° NW | 65° | 16h 09m |
| September equinox (Sep 22) | 6:59 AM | 89° E | 7:11 PM | 271° W | 42° | 12h 12m |
| December solstice (Dec 21) | 8:02 AM | 126° SE | 4:18 PM | 234° SW | 18° | 8h 16m |
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
Waterfalls photograph best in soft, even light: overcast days, deep shade, or the hour after sunrise before direct sun hits the water. Bright sun on white water blows highlights and adds harsh contrast.
| Month (15th) | Blue hour starts | Sunrise | Golden hour ends | Golden hour starts | Sunset | Blue hour ends | Daylight |
|---|---|---|---|---|---|---|---|
| January | 7:24 AM | 7:59 AM | 8:51 AM | 3:52 PM | 4:43 PM | 5:19 PM | 8h 44m |
| February | 6:48 AM | 7:20 AM | 8:05 AM | 4:48 PM | 5:33 PM | 6:05 PM | 10h 13m |
| March | 6:54 AM | 7:25 AM | 8:07 AM | 6:35 PM | 7:17 PM | 7:48 PM | 11h 51m |
| April | 5:48 AM | 6:21 AM | 7:04 AM | 7:20 PM | 8:03 PM | 8:36 PM | 13h 41m |
| May | 4:53 AM | 5:31 AM | 6:17 AM | 8:00 PM | 8:46 PM | 9:24 PM | 15h 15m |
| June | 4:27 AM | 5:09 AM | 5:59 AM | 8:27 PM | 9:16 PM | 9:58 PM | 16h 07m |
| July | 4:45 AM | 5:25 AM | 6:13 AM | 8:22 PM | 9:10 PM | 9:50 PM | 15h 45m |
| August | 5:31 AM | 6:05 AM | 6:49 AM | 7:44 PM | 8:28 PM | 9:03 PM | 14h 22m |
| September | 6:17 AM | 6:49 AM | 7:30 AM | 6:45 PM | 7:26 PM | 7:58 PM | 12h 37m |
| October | 7:00 AM | 7:32 AM | 8:15 AM | 5:40 PM | 6:23 PM | 6:55 PM | 10h 51m |
| November | 6:46 AM | 7:21 AM | 8:10 AM | 3:44 PM | 4:33 PM | 5:07 PM | 9h 12m |
| December | 7:21 AM | 7:58 AM | 8:53 AM | 3:22 PM | 4:17 PM | 4:54 PM | 8h 18m |
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 Cavern Falls, the Milky Way core is visible in a dark sky from May through July. June gives the longest window (about 2.7 hours on a moonless night), and the core peaks around 12° above the southern horizon. Our light-pollution model puts the sky at about Bortle 3 (rural sky), good enough for detailed Milky Way images.
| Month | Core visible (15th) | Hours | Max altitude | Direction |
|---|---|---|---|---|
| January | Below 10° in darkness | — | -5° | — |
| February | Below 10° in darkness | — | 4° | — |
| March | Below 10° in darkness | — | 9° | — |
| April | 4:01 AM – 4:11 AM | 0.2 | 11° | SSE → SSE |
| May | 1:58 AM – 2:48 AM | 0.8 | 12° | SSE → S |
| June | 11:59 PM – 2:39 AM | 2.7 | 12° | SSE → SSW |
| July | 12:07 AM – 12:47 AM | 0.7 | 12° | S → SSW |
| August | 10:37 PM – 10:37 PM | 0.0 | 10° | SSW → SSW |
| September | Below 10° in darkness | — | 8° | — |
| October | Below 10° in darkness | — | 4° | — |
| November | Below 10° in darkness | — | -5° | — |
| December | Below 10° in darkness | — | -20° | — |
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: 3 Bortle 3 — Rural sky. Some light domes sit on the horizon, but the Milky Way still looks complex overhead. Modeled zenith brightness ≈ 21.38 mag/arcsec². Aurora needs roughly Kp 4.5+ to show low on the northern horizon here.
Weather & best season
Long-term NASA satellite data for this area show July as the clearest month (about 44% average cloud cover) and January as the cloudiest (83%). August is the warmest month and December 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 | 58 | 68 | 69 | 83 | 91 | 91 | 94 | 94 | 93 | 78 | 64 | 58 |
| Low °F | 10 | 15 | 21 | 28 | 36 | 42 | 47 | 46 | 41 | 28 | 15 | 11 |
| Precip. (in) | 7.4 | 4.8 | 5.6 | 3.7 | 2.5 | 1.9 | 1.0 | 1.3 | 2.5 | 5.5 | 8.1 | 6.7 |
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 waterfall
- Spring snowmelt and the days after heavy rain give the strongest flow; late summer flow can drop to a trickle.
- Look for a foreground: a mossy boulder, a fallen log or the creek's leading lines make a stronger frame than the falls alone.
- Keep a microfiber cloth handy — spray drifts onto the lens, especially at the plunge pool.
- Bracket shutter speeds: 1/8 s, 1/2 s and 2 s give very different water textures and you can choose later.
- Scout in daylight if you plan to shoot at night or before sunrise.
Season: Peak flow is usually in late spring; autumn adds color around the falls, and winter can bring ice formations at colder locations.
Suggested gear: Tripod, Circular polarizer, 3–6 stop ND filter, Lens cloth, Waterproof footwear. Work out exposures with the depth of field, ND filter and NPF rule calculators.
Nearby photo spots
Other locations within 25 km of Cavern Falls, closest first.
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State Park
Fire Lookout
Mountain Peak
State Park
LighthouseLighthouseFAQ
When is the best time to photograph Cavern Falls?
What time is golden hour at Cavern Falls?
Where does the sun rise and set at Cavern Falls?
Can you see the Milky Way from Cavern Falls?
Do you need a permit to photograph at Cavern Falls?
How far is Cavern Falls from Friday Harbor?
Sources
Location data: 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.