Harvest Moon Frame Drops at Night

[Joenanners]

Okay I'm having huge frame drops at night I am at 30-60 fps during the day but it goes all the way down to 5-8 fps at night. I was wondering if anyone else has had a problem like this but I would also like to note I have tried disabling things like the fog and the lighting but to no success. Would appreciate any advice on how to sort fps settings as at the moment they are at the default ones given.