is it wrong to tell a girl how you truly feel about her?

there is this girl that we've had a thing with for almost 8 months and we've gone out on a couple dates and hung out. She is in school most of the year so i don't get to see her much at all and we don't talk too much but thats just how things are between us. couple months ago we both shared how we feel about each other but that she wasn't ready for a relationship due to her being away at school so much. but we've still stayed in touch here and there. i saw her and we went hiking just the two of us yesterday for the first time in 3 months cause she was away and will be going away again Monday for a few months again. Is it wrong of me or should i not tell her how i truly feel for her cause its stronger now than ever before or should i just not. i know she wont be ready for a relationship still and don't even know if she likes me like that anymore. she already know i like her cause we told each other right before she went away but don't think she knows how truly much i like her now more than ever. im not looking for me telling her how i feel to try to change her mind and date me.