How do you find out if the fall turnover had already occurred or not in a lake you are not familiar with?

Ask a fish. LOL, sorry I couldn't resist.

I would call a local guide service, or bait shop if available.

Go for a swim with a thermometer

If you have a boat with a sonar unit you can determine if a thermocline exists, no thermocline indicates the water column isn't layered and a lake must layered in temperature breaks to turn over. Not all lakes turn over.

If you are metering fish at all depths, without seeing a thermocline, this also indicates the water column is fairly uniform water temperature and the lake is stable and hasn't turned over recently. The water color isn't murky and doesn't have an odor is another indicator that the lake hasn't experienced a recent turn over. If you are catching fish it doesn't matter, if you are not; it makes a good excuse.

Tom

If you have a boat with a sonar unit you can determine if a thermocline exists, no thermocline indicates the water column isn't layered and a lake must layered in temperature breaks to turn over. Not all lakes turn over.

If you are metering fish at all depths, without seeing a thermocline, this also indicates the water column is fairly uniform water temperature and the lake is stable and hasn't turned over recently. The water color isn't murky and doesn't have an odor is another indicator that the lake hasn't experienced a recent turn over. If you are catching fish it doesn't matter, if you are not; it makes a good excuse.

Tom

Perfect! Thank you, Tom.

i was going to answer, but tom has already covered all the answers. great answers as usual tom. and, i would also say that you did a much better job explaining it than what i would have done.

bo