Coolant level my coolant light keeps flashing but after checking it is on min what could be wrong

Bad sensor

the lowering on the temp gauge indicates a lack of coolant around the bulb of the temp sender unit or a lack of flow around the cooling system
could be from low coolant level or blockage in the coolant system from forming ice ( 16 degrees is -8 degrees Celsius which is below freezing point of water)
I suggest that you check the antifreeze ratio in the cooling system and it should be no less than 50/50 to water
any thing less than 50 % antifreeze in the water will allow the coolant to freeze up which may be your problem
coolant condition should be checked every season as it does deteriorate over time and the % ratio will drop
topping up with normal water is another method of lowering the % point
check with a radiator shop or dealer service center to get the correct % of antifreeze for below freezing conditions and keep it at that point

I wouldnt worry. Maybe a level indicator thinks it is being depleted. Give it a while. If it becomes more frequent or your engine overheats check coolant levels in reservoir. Most people will tell you it is common to have an empty reservoir, but not i. Check for signs of leaks in your driveway and fluid on water pump. If those are fine keep in mind coolant will still leak from your head gasket! There are a million ways for your coolant system to go wrong and little time to prevent overheating. Watch temp gauge and low coolant display staying on for elongated periods. :)

Obviously it's temperature gauge light. Check for coolant level first. Then check for coolant leak. If coolant is leaking out of your car, the lower coolant levels in your engine will cause it to overheat. If you have your heater on and it starts blowing hot air instead of cool, your engine is low on coolant. This will cause to flash a warning light on your car's dashboard.

Check your dipstick for coolant in the oil. It could be a bad head gasket.

Also check your thermostat. It's a cheap enough part to replace.

The light should be for a low level sensor in your coolant reservoir. Check your coolant level (when vehicle is cold), if fluid level is ok then the sensor is probably the culprit.

Sounds like your sensor unit in your coolant overflow tank. Like nearly everything man made that floats, they will eventually leak (become water logged). This is a relatively cheap fix, as long as the light is coming on and the coolant level in the overflow tank is between the MIN and MAX lines in the overflow tank. This means that the float in there is dropping below the actual fluid level (watter logged) and you need to get a replacement sensor unit (aka sending unit) for the overflow tank.

Otherwise, if the coolant level in the overflow tank IS BELOW the MIN level line on the tank, then you are losing coolant somewhere and that is when things start to get expensive (might be a radiator problem, head gasket, cylinder head, heater core, etc).

Its a Low Coolant indication. Fill the reservoir to at least the MIN level.

Replace the coolant level sensor.

First check the coolant expansion tank and radiator for correct level. The radiator should be full (take the cap off when the engine is cold, doing this on a hot engine will cause hot coolant to spray out and possibly cause major burns). The expansion tank should be marked level-wise, either min-max, or min only, or max only. If the levels are right, your level sensor is probably bad. This sensor is located somewhere in the expansion tank.