Downloading Helvetica Weather 1.0 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. The bundle id for Helvetica Weather for Mac is com.raygunapps.hweathermac.
We recommend checking the downloaded files with any free antivirus. The latest version of the program can be installed on Mac OS X 10.7 or later. The application lies within Lifestyle Tools, more precisely Weather. This free Mac application was originally designed by Ray Gun Apps. The most popular version among Helvetica Weather for Mac users is 1.0.
From the developer:
Helvetica Weather is all about re-designing weather. Instead of using all of these images for the weather we instead show you the weather in one of the most readable typefaces available. On launch the app shows you the current temperature as well as the current condition for your zip code. If you swipe to the right you will uncover the forecast for your zip code.
You may want to check out more software for Mac, such as The Weather Network, Clear Day - Formerly Weather HD or Live Dock Weather, which might be related to Helvetica Weather.