The software works only on Windows operating system. I have downloaded the latest version from the official website and I was able to install it on Windows. Unfortunately, it's not possible to install the application on Mac, but there is a way out. Download WineBottler and install it on Mac. Once it's installed, transfer the executable file on Mac and run it through Wine. Wine is an application developed to run Windows software without installing Windows.
Download EastyWeather: http://proweatherstation.com/easyweather/easyweather.htm
After downloading the file, extract the archive and rename easyweather.exe.readme to easyweather.exe