
Grand Lake Saint Marys State Park
Celina, OH · Mercer County
Right Now
Partly Cloudy
Water
58°
Wind
15 mph
NW
Gusts
26 mph
Pressure
29.98
rising
Forecast - Thu, May 14
High / Low
64° / 40°
Wind
9 mph
gusts 21 mph
Precip
0%
UV
5
Sunrise
10:22 AM
Sunset
12:46 AM
Today Read
Grand Lake Saint Marys State ParkWind read
Calm
9 mph avg
Water read
58°
Cool-water mix
Air range
40° / 64°
today
Precip
0%
low concern
Today's forecast for Grand Lake Saint Marys State Park has calm wind, 40F to 64F air temperatures, 0% chance of precipitation, and 58F water.
Ask what to do at Grand Lake Saint Marys State Park today.
The planner reads this page's water temp, forecast, fish species, solunar timing, reports, and imagery context so you can decide what to throw, when to go, and when to move.
Today's AI read
Active-water pattern for Bluegill / Channel catfish
Active temps make wind edges, shallow cover, and feeding windows more important. Wind matters today; use it only where control stays safe. With a weak solunar score, favor stable weather windows.
Uses this lake data
Trip read from the AI planner
Short window onlyFishing Forecast
waning crescent
Major
2:58 PM - 5:28 PM
Minor
8:08 AM - 9:38 AM
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Detailed temperature readings across your lake.
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Fish Species
7Water Temperature History
Current
67°
May 24
Low
32°
Dec 14
Average
55°
Last 12 Months
Warmest avg: July (80°F)
Coolest avg: December (34°F)
Rapid warming: May → June (+13°F)
Sharpest cooling: October → November (-15°F)
Nearby Lakes
Fishing Forecast
2/5waning crescent
Water at 58°F -- good for cool-water species.
Fish Species
7Nearby Lakes
FAQ
About Grand Lake Saint Marys State Park
Grand Lake Saint Marys State Park covers 12896.00 acres (20.15 square miles)
Grand Lake Saint Marys State Park is located in Celina, Mercer County, OH. It is accessible to the public for outdoor activities.