The basic issue here, I think, is that, in Perl, "try" is spelled "eval" and "throw" is spelled "die". You've just run into the Perl exception-handling model and wrapping the call in eval is how this is intended to be handled.

So, what to do about it?

The most bare-bones way to deal with it would be

eval {
  weather_subroutine();
} or do {
  warn $@;
};  # <-- Note trailing semicolon; it *does* matter
[download]

You could go even more minimal with

eval {
  weather_subroutine();
}
warn $@ if $@;
[download]

but that has some weird edge cases where $@ can get messed up, so the eval { } or do { }; construct is more reliable.

If you want something more robust and/or with more familiar spellings, take a look at TryCatch or Try::Tiny. (The Try::Tiny synopsis shows how to use it to turn an exception into a warning, so you could even lift that example straight out of the docs.)