Grand Lake St. Marys Lighthouse is a lighthouse in Mercer County, Ohio. It sits roughly 7.5 km (4.7 mi) E of Celina. It dates from 1923. It is listed on the National Register of Historic Places.
The Grand Lake St. Marys Lighthouse, also known as the "Northwoods Lighthouse", is a historic lighthouse on Grand Lake St. Marys, a reservoir in the far western part of the U.S. state of Ohio. Located east of the city of Celina in Mercer County, the lighthouse was built in 1923, using a plan modeled after the Eddystone Lighthouse off the coast of Cornwall in the United Kingdom.From the Wikipedia article “Grand Lake St. Marys Lighthouse”, licensed under CC BY-SA 4.0.
Sunrise & sunset directions
At Grand Lake St. Marys Lighthouse the sunrise point swings a long way through the year: about 58° (ENE) at the June solstice and 121° (ESE) in late December. Sunset moves from 303° (WNW) in June to 239° (WSW) in December, and the midday sun climbs to 73° in summer but only 26° in winter.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 7:42 AM | 90° E | 7:50 PM | 271° W | 49° | 12h 08m |
| June solstice (Jun 21) | 6:08 AM | 58° ENE | 9:13 PM | 303° WNW | 73° | 15h 04m |
| September equinox (Sep 22) | 7:26 AM | 89° E | 7:37 PM | 271° W | 50° | 12h 11m |
| December solstice (Dec 21) | 7:59 AM | 121° ESE | 5:15 PM | 239° WSW | 26° | 9h 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
Lighthouses work at both ends of the day: blue hour when the beacon is lit, and golden hour when white towers take on warm tones.
| Month (15th) | Blue hour starts | Sunrise | Golden hour ends | Golden hour starts | Sunset | Blue hour ends | Daylight |
|---|---|---|---|---|---|---|---|
| January | 7:30 AM | 8:00 AM | 8:42 AM | 4:54 PM | 5:36 PM | 6:06 PM | 9h 36m |
| February | 7:05 AM | 7:33 AM | 8:11 AM | 5:35 PM | 6:13 PM | 6:41 PM | 10h 41m |
| March | 7:23 AM | 7:51 AM | 8:27 AM | 7:09 PM | 7:45 PM | 8:12 PM | 11h 54m |
| April | 6:32 AM | 7:00 AM | 7:37 AM | 7:40 PM | 8:17 PM | 8:45 PM | 13h 17m |
| May | 5:51 AM | 6:22 AM | 7:01 AM | 8:09 PM | 8:48 PM | 9:19 PM | 14h 26m |
| June | 5:34 AM | 6:08 AM | 6:49 AM | 8:30 PM | 9:11 PM | 9:44 PM | 15h 03m |
| July | 5:48 AM | 6:21 AM | 7:01 AM | 8:28 PM | 9:08 PM | 9:41 PM | 14h 48m |
| August | 6:20 AM | 6:49 AM | 7:27 AM | 8:00 PM | 8:37 PM | 9:07 PM | 13h 48m |
| September | 6:52 AM | 7:19 AM | 7:55 AM | 7:13 PM | 7:49 PM | 8:16 PM | 12h 29m |
| October | 7:22 AM | 7:49 AM | 8:26 AM | 6:22 PM | 6:59 PM | 7:27 PM | 11h 10m |
| November | 6:56 AM | 7:25 AM | 8:06 AM | 4:41 PM | 5:22 PM | 5:51 PM | 9h 57m |
| December | 7:24 AM | 7:55 AM | 8:39 AM | 4:29 PM | 5:13 PM | 5:44 PM | 9h 18m |
Local time (America/New York), 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 Grand Lake St. Marys Lighthouse, the Milky Way core is visible in a dark sky from March through September. June gives the longest window (about 4.7 hours on a moonless night), and the core peaks around 21° 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 | 5:55 AM – 5:55 AM | 0.0 | 11° | SE → SE |
| March | 5:06 AM – 6:16 AM | 1.2 | 17° | SE → SSE |
| April | 3:05 AM – 5:15 AM | 2.2 | 20° | SE → S |
| May | 1:00 AM – 4:20 AM | 3.3 | 21° | SE → S |
| June | 11:16 PM – 3:56 AM | 4.7 | 21° | SSE → SSW |
| July | 11:07 PM – 2:37 AM | 3.5 | 21° | S → SW |
| August | 10:20 PM – 12:30 AM | 2.2 | 20° | S → SW |
| September | 9:22 PM – 10:32 PM | 1.2 | 17° | SSW → SW |
| October | 8:30 PM – 8:30 PM | 0.0 | 11° | 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 ≈ 20.82 mag/arcsec². Aurora needs roughly Kp 6.5+ to show low on the northern horizon here.
Weather & best season
Long-term NASA satellite data for this area show September as the clearest month (about 46% average cloud cover) and January as the cloudiest (77%). 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 | 64 | 71 | 81 | 81 | 90 | 101 | 102 | 97 | 96 | 90 | 78 | 69 |
| Low °F | -14 | -10 | 3 | 21 | 25 | 40 | 47 | 47 | 37 | 27 | 10 | -9 |
| Precip. (in) | 2.5 | 2.4 | 3.0 | 3.7 | 4.3 | 4.2 | 3.7 | 3.4 | 3.1 | 3.0 | 3.0 | 2.8 |
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 lighthouse
- A telephoto from across a bay compresses the tower against cliffs or the moon.
- Many lighthouses are on private or Coast Guard property — check public access and opening hours.
- Moonrise or the Milky Way over the tower makes a classic night composition; plan with the azimuth tables.
- During blue hour, use 5–15 second exposures to capture the beam; check whether the light is still active.
- Shoot from the beach or a jetty to place the tower against open sky and sea.
- Tell someone where you're going in remote areas and carry the ten essentials.
Season: Summer brings open towers and tours; autumn and winter offer storms, fewer crowds and lower sun angles.
Suggested gear: Tripod, Telephoto lens, ND filter for smooth water, Rain cover. Work out exposures with the depth of field, ND filter and NPF rule calculators.
Nearby photo spots
Other locations within 25 km of Grand Lake St. Marys Lighthouse, closest first.
FAQ
When is the best time to photograph Grand Lake St. Marys Lighthouse?
What time is golden hour at Grand Lake St. Marys Lighthouse?
Where does the sun rise and set at Grand Lake St. Marys Lighthouse?
Can you see the Milky Way from Grand Lake St. Marys Lighthouse?
Do you need a permit to photograph at Grand Lake St. Marys Lighthouse?
How far is Grand Lake St. Marys Lighthouse from Celina?
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.