A cold day in July noun phrase
A way of saying that something never or unlikely happens.
It'll be a cold day in July before you defeat me.
It's going to be a cold day in July when I will meet him again. He broke up with me and decided to cut off any contact we once had.
Don't make plans that depend on something hoped before it has actually happened.
Don't make sure that the result will be good until it actually happens.
To consider or think about what will happen in the future
Signs or clues often precede important events that are about to happen
It refers to the fact that the weather is usually very hot in July.