The Dark Sky Weather Plugin
Plugin Name: darksky
Purpose: Display weather forecast icons and temperature information in a calendar using the Dark Sky weather API.
You must register at the https://developer.forecast.io/ website to obtain an API key (click the register link at the top of the page). Once you obtain this key, enter it in the plugin settings for the Dark Sky plugin located in the Joomla plugin manager. To display weather on a calendar, enter a latitude / longitude point in the Dark Sky settings located under the plugins tab in the calendar settings.
This plugin provides world-wide weather based on the latitude/longitude point entered in the calendar settings under the plugin tab. Forecast.io provides free access to their API for the first 1,000 calls. Zap Calendar caches its weather data for 60 minutes, so this limit should never be reached.