Grand Lake St. Marys — a lake in Mercer County, Ohio — is a popular subject for landscape photographers. It is part of Grand Lake St. Marys State Park. It sits roughly 7.1 km (4.4 mi) ESE of Celina.
Grand Lake St. Marys State Park is a public recreation area located on 13,500-acre (5,500 ha) Grand Lake in Mercer and Auglaize counties, Ohio. Grand Lake is the largest inland lake in Ohio in terms of area, but is shallow, with an average depth of only 5–7 feet (1.5–2.1 m). The state park is open for year-round recreation, including boating, fishing, swimming and hunting. The park consists of the lake and park facilities scattered all around the shore intermingled with private property and a facility operated by Wright State University. It is west of St. Marys, and southeast of Celina, 23 miles (37 km) southwest of Lima in the northwestern part of the state.From the Wikipedia article “Grand Lake St. Marys State Park”, licensed under CC BY-SA 4.0.
Sunrise & sunset directions
At Grand Lake St. Marys 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
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 | 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 | 5:49 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, 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 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.
- Check road and trail conditions with the managing agency before you go.
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.
Permits, drones & access
Drones: Drone rules in state parks vary by state and even by park — many require a permit or ban recreational drone flights. Check the park's rules and the FAA B4UFLY app before flying.
Nearby photo spots
Other locations within 25 km of Grand Lake St. Marys, closest first.
FAQ
When is the best time to photograph Grand Lake St. Marys?
What time is golden hour at Grand Lake St. Marys?
Where does the sun rise and set at Grand Lake St. Marys?
Can you see the Milky Way from Grand Lake St. Marys?
Do you need a permit to photograph at Grand Lake St. Marys?
How far is Grand Lake St. Marys 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.