To check the international codes https://www.mycodedetail.com is one the authentic site I found To get the JSON file of all countries unique woeid number https://codepen.io/shekhar-sajwan/pen/yLMjqZK
*It's Free database I do not guarantee for the complete list of world countries.
*You need to check out and verify spelling mistakes, and the most important thing to verify the data in JSON and SQL files I can not guarantee that record will be authentic.