@debal_das ,Thanks for response.
case 1: is it same for if weather data is 3rd party API?
case 2: Yes, do we have any example available ?
case 1: yes, I did the similar implementation with 3rd party API to populate stores based on UK postcode. We made ajax call to get list of stores and this approach helped the browser to continue loading the other content on the page simultaneously.
case 2: If you are dealing with huge json data then you could use Google's https://github.com/google/gson.
Please refer this : https://www.aemtutorial.info/2019/05/
The same point has been highlighted here also : https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/how-to-where-to-store-json-files-to-access-json-as-it-is-in-ui/m-p/272656