No. It can't have rained all day if it hasn't rained yet.
Interested in Language
It has been raining all day -means that it's still raining.
If it is not raining yet; what would be the correct form?
It rained all day?
"It has stopped raining."
Not a teacher
"It has stopped raining" doesn't mean "It hasn't rained yet".
It hasn't rained yet today = It has been dry all day. (No-one knows if it will rain later!)
It has been raining all day = It has not stopped raining at all and it is still raining.
It was raining earlier/It rained earlier = It is (probably) not raining now but it did rain at an unspecified time earlier.
It has stopped raining = It is not raining now but it was raining earlier.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.