I am trying to gather weather data in zip code level. When I run my code, a lot of the requests result in HTTP 500 errors, but when I retry the request with the same parameters, it will usually succeeds the second time. What are the reasons that cause this? Thanks.
That is probably being caused by intermittent issues with the issues with the systems used by the web services. You may have to write your code to keep trying until the download is successful.