Grand Lake Saint Marys State Park Weather Forecast

Today 20 Apr
- 39
- 52
Mostly Sunny
Tue 21 Apr
- 56
- 73
Chance Thunderstorms
Wed 22 Apr
- 54
- 74
Slight Chance Thunderstorms
Thu 23 Apr
- 61
- 79
Partly Sunny
Fri 24 Apr
- 55
- 79
Rain Showers Likely
Sat 25 Apr
- 50
- 70
Chance Rain Showers

Today 20 Apr
1. 12 am
2. 1 am
3. 2 am
4. 3 am
5. 4 am
6. 5 am
7. 6 am
8. 7 am
9. 8 am
10. 9 am
11. 10 am
12. 11 am
13. 12 pm
14. 1 pm
15. 2 pm
16. 3 pm
17. 4 pm
18. 5 pm
19. 6 pm
20. 7 pm
21. 8 pm
22. 9 pm
23. 10 pm
24. 11 pm
Tue 21 Apr
1. 12 am
2. 1 am
3. 2 am
4. 3 am
5. 4 am
6. 5 am
7. 6 am
8. 7 am
9. 8 am
10. 9 am
11. 10 am
12. 11 am
13. 12 pm
14. 1 pm
15. 2 pm
16. 3 pm
17. 4 pm
18. 5 pm
19. 6 pm
20. 7 pm
21. 8 pm
22. 11 pm
Wed 22 Apr
1. 2 am
2. 5 am
3. 8 am
4. 11 am
5. 2 pm
6. 5 pm
7. 8 pm
Thu 23 Apr
1. 2 am
2. 8 am
3. 2 pm
4. 8 pm
Fri 24 Apr
1. 2 am
2. 8 am
3. 2 pm
4. 8 pm
Sat 25 Apr
1. 2 am
2. 8 am
3. 2 pm
4. 8 pm
Sun 26 Apr
1. 2 am
2. 8 am
3. 2 pm
4. 8 pm

Today 20 Apr Mercer

Widespread frost this morning. Sunny. Highs in the lower 50s. North Winds around 5 Mph.

Tonight 20 Apr Mercer

Clear. Lows in the upper 30s. South Winds 5 to 10 Mph.

Grand Lake Saint Marys State Park Temperature Statistics

April Temperature

Versailles Darke County Airport (22.4 miles)

Lowest 30 January, 2026
-9.4 °F
Average 2026
37.8 °F
Highest 22 March, 2026
84.2 °F
Lowest 18 March, 2026
19.4 °F
Average March
49.2 °F
Highest 22 March, 2026
84.2 °F
Lowest 7 April, 2026
28.4 °F
Average April
58.1 °F
Highest 13 April, 2026
80.6 °F

Climate (2021–Present)

Versailles Darke County Airport (22.4 miles)

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Average Low 2021–2026
43.2 °F
Average 2021–2026
52.4 °F
Average High 2021–2026
61.7 °F

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Grand Lake Saint Marys State Park Weather Forecast

Today 20 Apr Mercer

Tonight 20 Apr Mercer

Tue 21 Apr Mercer

Tue 21 Apr Mercer

Wed 22 Apr Mercer

Wed 22 Apr Mercer

Thu 23 Apr Mercer

Thu 23 Apr Mercer

Fri 24 Apr Mercer

Fri 24 Apr Mercer

Sat 25 Apr Mercer

Sat 25 Apr Mercer

Sun 26 Apr Mercer

Temperature Forecast NOAA

Temperature Real-Time

Wilmington Radar

National Satellite

National Synoptic

Grand Lake Saint Marys State Park Temperature Statistics

April Temperature

Versailles Darke County Airport (22.4 miles)

Lowest 30 January, 2026

Average 2026

Highest 22 March, 2026

Lowest 18 March, 2026

Average March

Highest 22 March, 2026

Lowest 7 April, 2026

Average April

Highest 13 April, 2026

Climate (2021–Present)

Versailles Darke County Airport (22.4 miles)

Average Low 2021–2026

Average 2021–2026

Average High 2021–2026