No. You can read the PDF Edition of any issue you have downloaded to your computer whether you are connected to the Internet or not. If you are using Hinduism Today Navigator, just open the application and it will automatically take you to the current issue. If you have simply downloaded PDFs directly through this web site, find and open them in Acrobat.
However, you must be connected to the Internet to view the audio and video features, go to active links on the pages, including advertisers' websites, or to download another issue.