Is it considered valid to say my shahada alone?

i live in a small town with no mosques nearby and i was wondering if it is valid to say my shahada alone with only god and the angels as my witnesses i took my shahada once before in a mosque but i went away for another religion for awhile and i allways knew i was a muslim but i wanna recommit myself to islam and the ummah so is it ok to say my shahdada alone la illaha ila allah wa ash hadu ana muhammadan rasull allah