If you are using nvm for managing nodejs(which is the recommended way), you can easily ensure that the same version of nodejs is available in all terminal windows or tabs. Below are some helpful commands to achieve that.
To check your current, active node version
To check whats node versions are locally installed
To install a particular node version
nvm install v7.3.0
To set a certain node version as the default
nvm alias default v7.3.0
Hope this helps!