Lake Berryessa is a lake in Napa County, California. It sits roughly 18.7 km (11.6 mi) E of Angwin.
Lake Berryessa is the largest lake in Napa County, California, United States. This reservoir in the Vaca Mountains was formed following the construction of the Monticello Dam on Putah Creek in the 1950s. Since the early 1960s, this reservoir has provided water and hydroelectricity to the North Bay region of the San Francisco Bay Area. The reservoir was named after the Berryessa family of California; José Jesús and Sexto "Sisto" Berryessa were granted Rancho Las Putas in 1843.From the Wikipedia article “Lake Berryessa”, licensed under CC BY-SA 4.0.
Sunrise & sunset directions
At Lake Berryessa 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 302° (WNW) in June to 240° (WSW) in December, and the midday sun climbs to 75° in summer but only 28° in winter.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 7:13 AM | 90° E | 7:21 PM | 271° W | 51° | 12h 08m |
| June solstice (Jun 21) | 5:46 AM | 59° ENE | 8:37 PM | 302° WNW | 75° | 14h 52m |
| September equinox (Sep 22) | 6:57 AM | 89° E | 7:08 PM | 271° W | 52° | 12h 10m |
| December solstice (Dec 21) | 7:24 AM | 120° ESE | 4:52 PM | 240° WSW | 28° | 9h 28m |
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
Lakes reflect best in calm air — usually the first hour after sunrise, before breezes ripple the surface.
| Month (15th) | Blue hour starts | Sunrise | Golden hour ends | Golden hour starts | Sunset | Blue hour ends | Daylight |
|---|---|---|---|---|---|---|---|
| January | 6:57 AM | 7:26 AM | 8:06 AM | 4:32 PM | 5:12 PM | 5:41 PM | 9h 46m |
| February | 6:34 AM | 7:01 AM | 7:38 AM | 5:10 PM | 5:47 PM | 6:15 PM | 10h 47m |
| March | 6:55 AM | 7:21 AM | 7:56 AM | 6:41 PM | 7:16 PM | 7:43 PM | 11h 55m |
| April | 6:06 AM | 6:33 AM | 7:09 AM | 7:10 PM | 7:46 PM | 8:13 PM | 13h 12m |
| May | 5:28 AM | 5:58 AM | 6:36 AM | 7:37 PM | 8:14 PM | 8:44 PM | 14h 16m |
| June | 5:13 AM | 5:45 AM | 6:25 AM | 7:56 PM | 8:36 PM | 9:07 PM | 14h 51m |
| July | 5:27 AM | 5:57 AM | 6:36 AM | 7:55 PM | 8:34 PM | 9:04 PM | 14h 36m |
| August | 5:56 AM | 6:24 AM | 7:00 AM | 7:28 PM | 8:05 PM | 8:33 PM | 13h 41m |
| September | 6:25 AM | 6:51 AM | 7:26 AM | 6:44 PM | 7:19 PM | 7:45 PM | 12h 27m |
| October | 6:52 AM | 7:19 AM | 7:55 AM | 5:56 PM | 6:32 PM | 6:59 PM | 11h 13m |
| November | 6:24 AM | 6:52 AM | 7:31 AM | 4:18 PM | 4:57 PM | 5:25 PM | 10h 05m |
| December | 6:51 AM | 7:20 AM | 8:02 AM | 4:08 PM | 4:50 PM | 5:19 PM | 9h 29m |
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 Lake Berryessa, the Milky Way core is visible in a dark sky from March through September. June gives the longest window (about 5.2 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 | — | -2° | — |
| February | 5:06 AM – 5:26 AM | 0.3 | 13° | SE → SE |
| March | 4:25 AM – 5:45 AM | 1.3 | 19° | SE → SSE |
| April | 2:20 AM – 4:50 AM | 2.5 | 22° | SE → S |
| May | 12:21 AM – 4:01 AM | 3.7 | 23° | SE → S |
| June | 10:33 PM – 3:43 AM | 5.2 | 23° | SE → SSW |
| July | 10:26 PM – 2:16 AM | 3.8 | 23° | SSE → SW |
| August | 9:43 PM – 12:13 AM | 2.5 | 22° | S → SW |
| September | 8:49 PM – 10:19 PM | 1.5 | 19° | SSW → SW |
| October | 8:00 PM – 8:20 PM | 0.3 | 13° | SW → SW |
| November | Below 10° in darkness | — | 0° | — |
| 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 ≈ 20.66 mag/arcsec².
Weather & best season
Long-term NASA satellite data for this area show July as the clearest month (about 19% average cloud cover) and December as the cloudiest (57%). July is the warmest month and January 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 | 73 | 75 | 76 | 87 | 100 | 106 | 109 | 107 | 112 | 103 | 87 | 71 |
| Low °F | 25 | 27 | 28 | 30 | 35 | 42 | 48 | 48 | 45 | 37 | 27 | 24 |
| Precip. (in) | 4.7 | 5.1 | 3.7 | 1.9 | 0.8 | 0.2 | 0.0 | 0.0 | 0.1 | 1.3 | 2.9 | 6.2 |
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 lake
- For mirror reflections, get low and close to the water; the reflection grows with a lower camera.
- A polarizer can remove reflections to show the lakebed — or keep them, depending on rotation.
- Mist often lifts off lakes on cold mornings after warm days, especially in autumn.
- Include shoreline rocks, reeds or a log as foreground to give the reflection depth.
- Shoot RAW to keep the most latitude for high-contrast sunrise and sunset scenes.
Season: Autumn mornings bring mist and fall color; high-elevation lakes are usually ice-free only from early summer to mid-autumn.
Suggested gear: Tripod, Circular polarizer, Wide-angle lens, Waterproof boots. Work out exposures with the depth of field, ND filter and NPF rule calculators.
Nearby photo spots
Other locations within 25 km of Lake Berryessa, closest first.
Waterfall
State Park
Waterfall
State ParkCampgrounds nearby (Recreation.gov)
FAQ
When is the best time to photograph Lake Berryessa?
What time is golden hour at Lake Berryessa?
Where does the sun rise and set at Lake Berryessa?
Can you see the Milky Way from Lake Berryessa?
Do you need a permit to photograph at Lake Berryessa?
How far is Lake Berryessa from Angwin?
Sources
Location data: Wikidata, Wikipedia. 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.