I do not know if it will rain tomorrow.
I don't know if it'll rain tomorrow.
Occasional showers are possible tomorrow.
I don't know if it will rain tomorrow.
I don't know if it'll rain tomorrow.
I do not know if it will rain tomorrow.
I don't know if it will rain tomorrow.
I don't know if it'll rain tomorrow.
I don't think that it'll rain tomorrow.
I do not think it will rain tomorrow.