Tijuana Slough National Wildlife Refuge is a national wildlife refuge in San Diego County, California. It sits roughly 3.3 km (2.1 mi) SSW of Imperial Beach.
Tijuana Slough National Wildlife Refuge is a wildlife refuge in the most southwestern corner of the contiguous United States near the San Ysidro International Border. As a National Wildlife Refuge, it is administered by the U.S. Fish and Wildlife Service. It was established in 1980. The refuge forms the northern part of the Tijuana River National Estuarine Research Reserve, one of 22 National Estuarine Research Reserves created nationwide to enhance scientific and public understanding of estuaries, and thereby contribute to improved estuarine management. It is also part of the San Diego National Wildlife Refuge Complex.From the Wikipedia article “Tijuana Slough National Wildlife Refuge”, licensed under CC BY-SA 4.0.
Sunrise & sunset directions
At Tijuana Slough National Wildlife Refuge the sunrise point swings a long way through the year: about 61° (ENE) at the June solstice and 118° (ESE) in late December. Sunset moves from 299° (WNW) in June to 243° (WSW) in December, and the midday sun climbs to 81° in summer but only 34° in winter.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 6:53 AM | 90° E | 7:00 PM | 271° W | 57° | 12h 07m |
| June solstice (Jun 21) | 5:42 AM | 61° ENE | 8:00 PM | 299° WNW | 81° | 14h 18m |
| September equinox (Sep 22) | 6:37 AM | 89° E | 6:47 PM | 271° W | 58° | 12h 09m |
| December solstice (Dec 21) | 6:47 AM | 118° ESE | 4:48 PM | 243° WSW | 34° | 10h 00m |
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
Wildlife is most active in the first and last two hours of daylight — exactly when the light is warmest.
| Month (15th) | Blue hour starts | Sunrise | Golden hour ends | Golden hour starts | Sunset | Blue hour ends | Daylight |
|---|---|---|---|---|---|---|---|
| January | 6:25 AM | 6:51 AM | 7:28 AM | 4:29 PM | 5:06 PM | 5:33 PM | 10h 15m |
| February | 6:07 AM | 6:32 AM | 7:06 AM | 5:01 PM | 5:35 PM | 6:00 PM | 11h 02m |
| March | 6:35 AM | 7:00 AM | 7:32 AM | 6:24 PM | 6:57 PM | 7:21 PM | 11h 57m |
| April | 5:54 AM | 6:20 AM | 6:53 AM | 6:46 PM | 7:19 PM | 7:44 PM | 12h 59m |
| May | 5:24 AM | 5:51 AM | 6:26 AM | 7:06 PM | 7:41 PM | 8:08 PM | 13h 50m |
| June | 5:13 AM | 5:41 AM | 6:18 AM | 7:22 PM | 7:58 PM | 8:27 PM | 14h 17m |
| July | 5:25 AM | 5:52 AM | 6:28 AM | 7:22 PM | 7:58 PM | 8:26 PM | 14h 05m |
| August | 5:47 AM | 6:13 AM | 6:47 AM | 7:01 PM | 7:35 PM | 8:01 PM | 13h 22m |
| September | 6:08 AM | 6:33 AM | 7:06 AM | 6:24 PM | 6:56 PM | 7:21 PM | 12h 23m |
| October | 6:28 AM | 6:53 AM | 7:26 AM | 5:44 PM | 6:17 PM | 6:42 PM | 11h 24m |
| November | 5:53 AM | 6:19 AM | 6:55 AM | 4:13 PM | 4:49 PM | 5:15 PM | 10h 30m |
| December | 6:17 AM | 6:44 AM | 7:21 AM | 4:08 PM | 4:45 PM | 5:12 PM | 10h 01m |
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 Tijuana Slough National Wildlife Refuge, the Milky Way core is visible in a dark sky from February through October. June gives the longest window (about 6.3 hours on a moonless night), and the core peaks around 29° above the southern horizon. Our light-pollution model puts the sky at about Bortle 7 (suburban / urban transition), so expect visible sky glow; drive away from towns for better results.
| Month | Core visible (15th) | Hours | Max altitude | Direction |
|---|---|---|---|---|
| January | Below 10° in darkness | — | 1° | — |
| February | 4:18 AM – 5:08 AM | 0.8 | 18° | SE → SE |
| March | 3:29 AM – 5:29 AM | 2.0 | 25° | SE → SSE |
| April | 1:25 AM – 4:45 AM | 3.3 | 28° | SE → S |
| May | 11:25 PM – 4:15 AM | 4.8 | 29° | SE → SSW |
| June | 9:40 PM – 4:00 AM | 6.3 | 29° | SE → SW |
| July | 9:36 PM – 2:26 AM | 4.8 | 29° | SSE → SW |
| August | 9:04 PM – 12:24 AM | 3.3 | 29° | S → SW |
| September | 8:19 PM – 10:29 PM | 2.2 | 25° | SSW → SW |
| October | 7:39 PM – 8:29 PM | 0.8 | 18° | SW → SW |
| November | Below 10° in darkness | — | 3° | — |
| December | Below 10° in darkness | — | -18° | — |
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: 7 Bortle 7 — Suburban / urban transition. The whole sky has a grey-white glow; the Milky Way is invisible to the eye. Modeled zenith brightness ≈ 18.67 mag/arcsec².
Weather & best season
Long-term NASA satellite data for this area show January as the clearest month (about 50% average cloud cover) and June as the cloudiest (81%). September is the warmest month and February 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 | 74 | 77 | 81 | 78 | 81 | 78 | 83 | 83 | 86 | 89 | 82 | 73 |
| Low °F | 48 | 48 | 51 | 50 | 52 | 54 | 57 | 59 | 58 | 57 | 51 | 51 |
| Precip. (in) | 1.6 | 2.2 | 1.1 | 0.7 | 0.2 | 1.1 | 0.1 | 0.1 | 0.1 | 0.6 | 1.0 | 1.9 |
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 national wildlife refuge
- Use auto-loop roads as mobile blinds; animals often tolerate vehicles more than people on foot.
- Stay on designated routes and keep a respectful distance — if an animal changes behavior, you are too close.
- A 400–600 mm lens (or a crop body) is the usual tool for birds.
- Fast shutter speeds (1/2000 s+) freeze wingbeats; raise ISO rather than lose the shot.
- Scout in daylight if you plan to shoot at night or before sunrise.
Season: Spring and autumn migration are the highlights; winter brings waterfowl to many southern refuges.
Suggested gear: Telephoto lens (400 mm+), Bean bag for car window, Binoculars. Work out exposures with the depth of field, ND filter and NPF rule calculators.
Permits, drones & access
Drones: Launching or landing drones on National Wildlife Refuge lands generally requires a special use permit from the refuge manager, and wildlife disturbance rules apply everywhere.
Nearby photo spots
Other locations within 40 km of Tijuana Slough National Wildlife Refuge, closest first.
Canyon
State Park
National Wildlife Refuge
Lighthouse
Scenic Viewpoint
Lighthouse
Scenic Viewpoint
Scenic Viewpoint
Scenic ViewpointFAQ
When is the best time to photograph Tijuana Slough National Wildlife Refuge?
What time is golden hour at Tijuana Slough National Wildlife Refuge?
Where does the sun rise and set at Tijuana Slough National Wildlife Refuge?
Can you see the Milky Way from Tijuana Slough National Wildlife Refuge?
Do you need a permit to photograph at Tijuana Slough National Wildlife Refuge?
How far is Tijuana Slough National Wildlife Refuge from Imperial Beach?
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.