阻止通过http加载混合活动内容

I'm running my website over https and I'm trying to call an API which is on http what did I try is :

//api.openweathermap.org/data/2.5/weather http://api.openweathermap.org/data/2.5/weather

but didn't succeed can you please suggest.

There does not appear to be HTTPS support for this API. From this question on the OpenWeatherMap forums,

HTTPS is available only in Professional and Enterprise accounts. In Free account this feature is not available.

See this answer from another SO post where the API call is made outside and served separately.