Check it out on CodePen: http://codepen.io/pawelkleczek/full/WGPRGw/
Weather viewer API uses geolocation function (Web API) to determine users exact location. Afterwards it prepares a query to Apixu API to collect data about users location current weather information and displays it to the user. Mechanics uses some javascript, and Web API. User can change degrees from Celsius to Fahrenheit.