WordPress OpenWeatherMap Weather Forecast Plugin Lite show current weather data and weather forecast data for a city that can be set as default city from admin plugin settings page and from the shortcode.
The shortcode you have to put use is [cspdy_owm_shortcode_content]. The shortcode can have the city inside it like [cspdy_owm_shortcode_content city="CITY NAME"] or can contain unit like [cspdy_owm_shortcode_content city="new york" unit="metric"].
The unit and city provided in shortcode will replace the default city and unit that you set in the settings page. There are both the free and premium version available.
This plugin using third party API keys. below is given the API with the hyperlink from where you can get it: