Engine oil temperature light?

Evening gents, my light has come on just for a minute or two whilst driving then comes off has only ever came on when I’m nearly at my destination so I just risk it for a biscuit and it comes off before I arrive. I am driving a black car in a very hot British summer with not much of a breeze so hoping it’s just ambient temps combined with a fair amount of 40/60min drives and not a water pump, thoughts?